- Update references to the settings page to use new url across docs
and code
- Rename desktop and web settings page to settigns.html instead of
config[ure].html
- Make the docs overview page available at docs.khoj.dev root instead of
under docs.khoj.dev/docs path
- Remove the new landing page, it is unnecessary.
- Remove /docs path prefix from links to internal doc pages
- Remove .md path suffix in internal doc pages for consistency
