Revert "Try changing Home: README.md to index.md"

This reverts commit 6af163d.

Author: mpilgrem

mkdocs.yml

@@ -13,7 +13,7 @@ extra_javascript:
 - js/searchhack.js
 
 nav:
-- Home: index.md
+- Home: README.md
 - Changelog: ChangeLog.md
 - Tool documentation:
   - Install/upgrade: install_and_upgrade.md