Chore: Remove more GH references (#2374)

CONTRIBUTING.md

@@ -7,7 +7,7 @@ There are multiple ways to contribute:
 
 - Translating MapComplete to your own language can be done
   on [the Weblate website](https://translate.mapcomplete.org/projects/mapcomplete/)
-- If you encounter a bug, the [issue tracker](https://github.com/pietervdvn/MapComplete/issues) is the place to be
+- If you encounter a bug, the [issue tracker](https://source.mapcomplete.org/MapComplete/MapComplete/issues) is the place to be
 - A good start to contribute is to create a single map layer showing features which interest you. Read more about [making your own theme](/Docs/Making_Your_Own_Theme.md).
 - Feel free to hop in [our chat channel on matrix](https://app.element.io/#/room/#MapComplete:matrix.org)
 - If you want to improve a theme, create a new theme, spot a typo in the repo... the best way is to open a pull request. 
@@ -19,9 +19,9 @@ Rights of contributors
 -----------------------
 
 If you have write access to the repository, you can make a fork of an already existing branch and push this new branch
-to GitHub. This means that this branch will be _automatically built_ and be **deployed**
-to `https://pietervdvn.github.io/mc/<branchname>`. You can see the deploy process
-on [GitHub Actions](https://github.com/pietervdvn/MapComplete/actions). Don't worry about pushing too much. These
+to Forgejo. This means that this branch will be _automatically built_ and be **deployed**
+to `https://builds.mapcomplete.org/<branchname>`. You can see the deploy process
+on [Forgejo Actions](https://source.mapcomplete.org/MapComplete/MapComplete/actions). Don't worry about pushing too much. These
 deploys are free and totally automatic. They might fail if something is wrong, but this will hinder no one.
 
 Additionally, some other maintainer might step in and merge the latest develop with your branch, making later pull