Fixed code block style (MD040) in the Extension Developer Guide (#5434)

* Fixed errors in the extension dev guide

* Fixed php code block

Author: jeff-matthews

guides/v2.2/ext-best-practices/extension-coding/example-module-adminpage.md

@@ -36,6 +36,7 @@ In the module's root directory, create the file `composer.json`. This file gives
 For more information see: [`composer.json`]({{ page.baseurl }}/extension-dev-guide/build/composer-integration.html).
 
 {% collapsible File content for composer.json %}
+
  ```json
     {
       "name": "mycompany/sample-module-minimal",
@@ -57,6 +58,7 @@ For more information see: [`composer.json`]({{ page.baseurl }}/extension-dev-gui
       }
     }
  ```
+
 {% endcollapsible %}
 
 #### `registration.php`
@@ -66,6 +68,7 @@ In the module's root directory, create the file `registration.php`. This file re
 For more information see: [registering your component]({{ page.baseurl }}/extension-dev-guide/build/component-registration.html).
 
 {% collapsible File content for registration.php %}
+
   ```php
     <?php
     \Magento\Framework\Component\ComponentRegistrar::register(
@@ -74,6 +77,7 @@ For more information see: [registering your component]({{ page.baseurl }}/extens
         __DIR__
     );
  ```
+
 {% endcollapsible %}
 
 #### `etc/module.xml`
@@ -83,13 +87,15 @@ In the module's root directory, create a new directory called `etc`. Under that
 For more information see: [naming your component]({{ page.baseurl }}/extension-dev-guide/build/create_component.html).
 
 {% collapsible File content for module.xml %}
+
  ```xml
     <?xml version="1.0"?>
     <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
       <module name="MyCompany_ExampleAdminNewPage" setup_version="1.0.0">
       </module>
     </config>
  ```
+
 {% endcollapsible %}
 
 ### Routing and navigation
@@ -117,6 +123,7 @@ The following parts make up the generated page request link to the **Hello World
 
 [//]: # (Stop list rendering before collapsible, see: https://github.com/magento/devdocs/issues/2655)
 {% collapsible File content for menu.xml %}
+
  ```xml
     <?xml version="1.0"?>
     <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Backend:etc/menu.xsd">
@@ -126,13 +133,15 @@ The following parts make up the generated page request link to the **Hello World
         </menu>
     </config>
  ```
+
 {% endcollapsible %}
 
 #### `etc/adminhtml/routes.xml`
 {:.no_toc}
 Under `etc/adminhtml` create the file `routes.xml`. The contents of this  XML file tells Magento to route requests that use the `frontName` `exampleadminnewpage` to this module.
 
 {% collapsible File content for routes.xml %}
+
  ```xml
   <?xml version="1.0"?>
   <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
@@ -143,6 +152,7 @@ Under `etc/adminhtml` create the file `routes.xml`. The contents of this  XML fi
       </router>
   </config>
  ```
+
 {% endcollapsible %}
 
 ### Page controller
@@ -159,6 +169,7 @@ mkdir -p Controller/Adminhtml/HelloWorld
 
 Inside `Controller/Adminhtml/HelloWorld` directory, create the file `Index.php`. This file is the class assigned to the default Index action for the `HelloWorld` controller. Since the admin area serves this page, the file belongs in the `Adminhtml` directory, and the class itself extends [`\Magento\Backend\App\Action`]({{ site.mage2bloburl }}/{{ page.guide_version }}/app/code/Magento/Backend/App/Action.php){:target="_blank"}.
 {% collapsible File content for Index.php %}
+
  ```php
     <?php
       namespace MyCompany\ExampleAdminNewPage\Controller\Adminhtml\HelloWorld;
@@ -196,6 +207,7 @@ Inside `Controller/Adminhtml/HelloWorld` directory, create the file `Index.php`.
       }
     ?>
  ```
+
 {% endcollapsible %}
 
 ### Page view
@@ -219,6 +231,7 @@ This file defines the [layout](https://glossary.magento.com/layout) and structur
 The name of this file uses the following pattern: *routeId*\_*controller*\_*action*.xml
 
 {% collapsible File content for exampleadminnewpage_helloworld_index.xml %}
+
  ```xml
     <?xml version="1.0"?>
     <page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
@@ -234,6 +247,7 @@ The name of this file uses the following pattern: *routeId*\_*controller*\_*acti
         </body>
     </page>
  ```
+
 {% endcollapsible %}
 
 #### `view/adminhtml/templates/helloworld.phtml`
@@ -242,9 +256,11 @@ The name of this file uses the following pattern: *routeId*\_*controller*\_*acti
 This template file contains the actual page content for the **Hello World** page.
 
 {% collapsible File content for helloworld.phtml %}
+
 ```html
     <p>Hello World!</p>
- ```
+```
+
 {% endcollapsible %}
 
 ### Full module directory structure

guides/v2.2/extension-dev-guide/build/module-file-structure.md

@@ -45,7 +45,7 @@ Additional folders can be added for configuration and other ancillary functions
 
 A typical [theme](https://glossary.magento.com/theme) file structure can look like the following:
 
-~~~
+```tree
 ├── composer.json
 ├── etc
 │   └── view.xml
@@ -81,7 +81,7 @@ A typical [theme](https://glossary.magento.com/theme) file structure can look li
         ├── navigation-menu.js
         ├── responsive.js
         └── theme.js
-~~~
+```
 
 #### Common directories
 {:.no_toc}

guides/v2.2/extension-dev-guide/cache/page-caching/public-content.md

@@ -117,7 +117,7 @@ For another example of a context class, see [Magento/Framework/App/Http/Context]
 
 Use the `X-Magento-Vary` cookie to transfer context on the HTTP layer. HTTP proxies can be configured to calculate a unique identifier for cache based on the cookie and URL. For example, [our sample Varnish 4 configuration]({{ site.mage2bloburl }}/{{ page.guide_version }}/app/code/Magento/PageCache/etc/varnish4.vcl#L63-L68){:target="_blank"} uses the following:
 
-```
+```conf
 sub vcl_hash {
     if (req.http.cookie ~ "X-Magento-Vary=") {
         hash_data(regsub(req.http.cookie, "^.*?X-Magento-Vary=([^;]+);*.*$", "\1"));

guides/v2.2/extension-dev-guide/cache/partial-caching/database-caching.md

@@ -36,12 +36,18 @@ To modify `di.xml`:
 1.	Log in to the Magento server as, or switch to, the [Magento file system owner].
 2.	Enter the following commands to make a copy of `di.xml`:
 
-		cd <magento_root>/app/etc
-		cp di.xml di.xml.bak
+    ```bash
+    cd <magento_root>/app/etc
+    ```
+
+    ```bash
+    cp di.xml di.xml.bak
+    ```
 
 3.	Open `di.xml` in a text editor and locate the following block:
 
-		<type name="Magento\Framework\App\Cache\Frontend\Pool">
+    ```xml
+    <type name="Magento\Framework\App\Cache\Frontend\Pool">
            <arguments>
               <argument name="frontendSettings" xsi:type="array">
                   <item name="page_cache" xsi:type="array">
@@ -59,6 +65,7 @@ To modify `di.xml`:
               </argument>
            </arguments>
         </type>
+    ```
 
 	The `<type name="Magento\Framework\App\Cache\Frontend\Pool">` node configures options for the in-memory pool of all frontend cache instances.
 
@@ -67,26 +74,26 @@ To modify `di.xml`:
 4.	Replace the entire block with the following:
 
     ```xml
-		<type name="Magento\Framework\App\Cache\Frontend\Pool">
-        	<arguments>
-            	<argument name="frontendSettings" xsi:type="array">
-            	    <item name="page_cache" xsi:type="array">
+    <type name="Magento\Framework\App\Cache\Frontend\Pool">
+          <arguments>
+              <argument name="frontendSettings" xsi:type="array">
+                  <item name="page_cache" xsi:type="array">
                         <item name="backend" xsi:type="string">database</item>
                     </item>
                     <item name="<your cache id>" xsi:type="array">
                         <item name="backend" xsi:type="string">database</item>
                     </item>
-           		</argument>
-        	</arguments>
-    	</type>
-    	<type name="Magento\Framework\App\Cache\Type\FrontendPool">
-        	<arguments>
-         	   <argument name="typeFrontendMap" xsi:type="array">
-         	       <item name="backend" xsi:type="string">database</item>
-         	   </argument>
-        	</arguments>
-    	</type>
-      ```
+              </argument>
+          </arguments>
+    </type>
+    <type name="Magento\Framework\App\Cache\Type\FrontendPool">
+          <arguments>
+              <argument name="typeFrontendMap" xsi:type="array">
+                 <item name="backend" xsi:type="string">database</item>
+              </argument>
+          </arguments>
+    </type>
+    ```
 
     where `<your cache id>` is your unique cache identifier.
 
@@ -106,30 +113,37 @@ To enable database caching using a custom cache frontend, you must modify `<mage
 1.	Log in to the Magento server as, or switch to, the [Magento file system owner].
 2.	Enter the following commands to make a copy of `env.php`:
 
-		cd <magento_root>/app/etc
-		cp env.php env.php.bak
+    ```bash
+    cd <magento_root>/app/etc
+    ```
+
+    ```bash
+    cp env.php env.php.bak
+    ```
 
 3.	Open `env.php` in a text editor and add the following anywhere, such as before `'cache_types' =>`:
 
-		'cache' => [
-		    'frontend' => [
-		        '<unique frontend id>' => [
-		             <cache options>
-		        ],
-		    ],
-		    'type' => [
-		         <cache type 1> => [
-		             'frontend' => '<unique frontend id>'
-		        ],
-		    ],
-		    'type' => [
-		         <cache type 2> => [
-		             'frontend' => '<unique frontend id>'
-		        ],
-		    ],
-		],
-
-	An example is shown in [Configuration examples].
+    ```php
+    'cache' => [
+        'frontend' => [
+            '<unique frontend id>' => [
+                 <cache options>
+            ],
+        ],
+        'type' => [
+             <cache type 1> => [
+                 'frontend' => '<unique frontend id>'
+            ],
+        ],
+        'type' => [
+             <cache type 2> => [
+                 'frontend' => '<unique frontend id>'
+            ],
+        ],
+    ],
+    ```
+
+    An example is shown in [Configuration examples].
 
 4.	Save your changes to `env.php` and exit the text editor.
 5.	Continue with the next section.
@@ -144,16 +158,21 @@ Use the following steps:
 2.	Clear the current cache directories:
 
     ```bash
-		rm -rf <magento_root>/var/cache/* <magento_root>/var/page_cache/* <magento_root>/generated/metadata/* <magento_root>/generated/code/*
+    rm -rf <magento_root>/var/cache/* <magento_root>/var/page_cache/* <magento_root>/generated/metadata/* <magento_root>/generated/code/*
     ```
 
 3.	In a web browser, go to any cacheable page (such as the [storefront](https://glossary.magento.com/storefront) front door page).
 
 	If exceptions display, verify `di.xml` syntax and try again. (To see exceptions in the browser, you must [enable developer mode].)
 4.	Enter the following commands:
 
-		ls <magento_root>/var/cache/*
-		ls <magento_root>/var/page_cache/*
+    ```bash
+    ls <magento_root>/var/cache/*
+    ```
+
+    ```bash
+    ls <magento_root>/var/page_cache/*
+    ```
 
     {:.bs-callout .bs-callout-info }
     Due to a known issue, a custom cache frontend still results in some objects being cached to the file system; however, fewer assets are cached compared to file system caching.

guides/v2.2/extension-dev-guide/cli-cmds/cli-howto.md

@@ -95,8 +95,13 @@ You can style the output text by using `<error>This is an error message</error>`
 
 3.	Clean the [cache](https://glossary.magento.com/cache) and compiled code directories:
 
-		cd <magento_root>/var
-		rm -rf cache/* page_cache/* di/* generation/*
+    ```bash
+    cd <magento_root>/var
+    ```
+
+    ```bash
+    rm -rf cache/* page_cache/* di/* generation/*
+    ```
 
 ## Add CLI commands using the Composer autoloader {#cli-autoload}
 
@@ -105,4 +110,3 @@ To be added at a later time.
 #### Related topic
 
 [Command naming guidelines]({{ page.baseurl }}/extension-dev-guide/cli-cmds/cli-naming-guidelines.html)
-