refactor(docs): indent markdown-extensions block in mkdocs.yml

mkdocs.yml

@@ -43,18 +43,18 @@ theme:
     icon: library_books
 
 markdown_extensions:
-- admonition
-- codehilite:
+  - admonition
+  - codehilite:
       linenums: true
-- toc:
+  - toc:
       permalink: True
-- footnotes
-- tables
-- plantuml_markdown:
+  - footnotes
+  - tables
+  - plantuml_markdown:
       server: http://plantuml.com/plantuml
       format: svg
-- pymdownx.emoji:
+  - pymdownx.emoji:
       emoji_generator: !!python/name:pymdownx.emoji.to_svg
-- pymdownx.tasklist
-- pymdownx.details
-- pymdownx.superfences
+  - pymdownx.tasklist
+  - pymdownx.details
+  - pymdownx.superfences