[docs] Replace Markdown in HTML with pure HTML

Author: salkinium

docs/index.md.in

@@ -1,7 +1,7 @@
 <!-- This file is generated by tools/scripts/synchronize_docs.py! -->
 # modm: a barebone embedded library generator
 <center>
-![](images/logo.svg)
+<img src="images/logo.svg"/>
 </center>
 {{content}}
 

docs/mkdocs.yml

@@ -74,7 +74,6 @@ markdown_extensions:
   - pymdownx.tasklist:
       custom_checkbox: true
   - pymdownx.tilde
-  - md_in_html
 
 nav:
   - Home:

docs/src/how-modm-works.md

@@ -14,7 +14,7 @@ You can generate more than just code, in this example, lbuild also generates a
 build system which then compiles and links the application into a executable.
 
 <center>
-![](images/system-overview.svg)
+<img src="images/system-overview.svg"/>
 </center>
 
 We've also put a lot of thought into modm-devices, about what data to extract,