MC-800: [Doc] Create Custom Content Block

- Fixed file paths in documentation

Author: Michael Yu

app/code/Magento/PageBuilder/docs/how-to-create-custom-pagebuilder-content-type-container.md

@@ -499,8 +499,8 @@ And inside it should have:
 
 In order for the icons to work, you have to create the following files:
 ``` xml
-view/web/css/images/content-type/custom-container-group/appearance/left.svg
-view/web/css/images/content-type/custom-container-group/appearance/right.svg
+view/adminhtml/web/css/images/content-type/custom-container-group/appearance/left.svg
+view/adminhtml/web/css/images/content-type/custom-container-group/appearance/right.svg
 ```
 
 ## Templates