actually update to new version of material theme (https://squidfunk.g…

…ithub.io/mkdocs-material/releases/5/#how-to-upgrade)

mkdocs.yml

@@ -1,7 +1,7 @@
 site_name: Flux
 site_description: Documentation for Flux, the GitOps Kubernetes operator.
 site_author: The Flux contributors
-site_url: https://docs.fluxcd.io/
+site_url: https://docs.fluxcd.io
 
 # Repository
 repo_name: fluxcd/flux
@@ -12,8 +12,6 @@ theme:
   name: material
   logo: _files/[email protected]
   language: en
-  feature:
-    tabs: false
   palette:
     primary: blue
     accent: indigo
@@ -25,18 +23,14 @@ extra_css:
 
 plugins:
   - search
-    #  - redirects:
-    #  redirect_maps:
-    #    'guides/upgrading-to-ga.md': 'how-to/upgrade-to-ga.md'
-    #    'guides/upgrading-to-beta.md': 'how-to/upgrade-to-beta.md'
 
 markdown_extensions:
   - admonition
   - codehilite:
       guess_lang: false
   - toc:
       permalink: true
-  - pymdownx.superfences
+  - pymdownx.tabbed
 
 nav:
   - Introducing Flux: introduction.md