mkdocs / use codehilite engine for syntax highlighting

.github/workflows/mkdocs.yml

@@ -18,6 +18,7 @@ jobs:
         python -m pip install --upgrade pip
         pip install mkdocs
         pip install mkdocs-material
+        pip install pygments
     - name: Build doc
       run: |
         git pull

mkdocs.yml

@@ -2,5 +2,4 @@ site_name: IXWebSocket
 theme:
   name: 'material'
 markdown_extensions:
-  - fenced_code
-  - tables
+  - codehilite