move contributing to the getting started section and make overview to…

…p level tab for documentation so menu button on mobile doesn't need to hit back button first to see everything

mkdocs.yml

@@ -14,14 +14,14 @@ copyright: Copyright © 2020 - 2021 Arkadii Ivanov
 
 # Page tree
 nav:
-  - Overview: 
-    - Overview: index.md
-    - Contributing: contributing.md
+  - Overview: index.md
 
   - Getting started:
     - Installation: getting-started.md
     - Samples: samples.md
     - License: license.md
+    - Contributing: contributing.md
+
 
   - Components: 
     - Overview: component/overview.md