fix & simplify docs

Author: jiwon-oai

mkdocs.yml

@@ -71,22 +71,11 @@ nav:
           - icons: api/chatkit/icons.md
   - Release process / changelog: release.md
   - ChatKit JS Docs: https://openai.github.io/chatkit-js/
+
 markdown_extensions:
-  - pymdownx.superfences:
-      custom_fences:
-        - name: mermaid
-          class: mermaid
-          format: !!python/name:pymdownx.superfences.fence_code_format
-  - admonition
-  - attr_list
-  - md_in_html
-  - pymdownx.details
-  - pymdownx.highlight:
-      anchor_linenums: true
-      line_spans: __span
-      pygments_lang_class: true
-  - pymdownx.inlinehilite
-  - pymdownx.snippets
+  - fenced_code
+  - codehilite
+  - pymdownx.highlight
   - pymdownx.superfences
 
 extra_css: