Change readme to point to online docs as setup seems old

doc/website/README.md

@@ -2,23 +2,7 @@
 
 This is the website for the [XDG Desktop Portal project](https://github.com/flatpak/xdg-desktop-portal).
 
-## Setup
+## Development
 
-The process of setting up the site locally consists of:
-
-- Install ruby [gem bundler](https://bundler.io/). On [Fedora](https://getfedora.org/)/in the [Toolbx](https://containertoolbx.org) you do:
-
-```
-toolbox enter
-sudo dnf install rubygem-bundler
-cd xdg-desktop-portal/doc/website
-bundle install
-```
-
-- Test the site locally:
-
-```
-bundle exec jekyll s
-```
-
-- `git commit` your changes and create a merge request. After review, the merged changes get automatically deployed to the site.
+The contribution guidelines have been moved to the online documentation:
+https://flatpak.github.io/xdg-desktop-portal/docs/for-contributors.html