Enable mkdocs includes and linked tabs

mkdocs.template.yml

@@ -9,6 +9,7 @@ theme:
   features:
     - navigation.instant
     - navigation.indexes
+    - content.tabs.link
 site_dir: 'html'
 extra:
   social:
@@ -32,6 +33,7 @@ plugins:
       exclude:
         - library/*
         - vendor/*
+  - include-markdown
 extra_javascript: []
 extra_css:
   - css/theme.css