Fixed code highlighting in docs

Author: Sylvain MARIE

docs/mkdocs.yml

@@ -7,11 +7,14 @@ nav:
     - Home: index.md
     - Usage details: usage.md
     - Changelog: changelog.md
+
 theme: material  # readthedocs  mkdocs
 
 markdown_extensions:
+  - pymdownx.highlight  # see https://squidfunk.github.io/mkdocs-material/reference/code-blocks/#highlight
+  - pymdownx.superfences # same as above as well as code blocks inside other blocks
   - admonition  # to add notes such as http://squidfunk.github.io/mkdocs-material/extensions/admonition/
-  - codehilite:
-      guess_lang: false
+#  - codehilite:
+#      guess_lang: false
   - toc:
-      permalink: true
+      permalink: true