Stop referring to the Google Group; It was shut down.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

Contact.md

@@ -6,12 +6,12 @@ Please follow [our guide lines](https://github.com/git-for-windows/git/wiki/Issu
 
 # I have a question!
 
-We have a [mailing list](https://groups.google.com/forum/#!forum/git-for-windows). It is actually a Google Group which can be used as if it were a forum, too.
+We have [GitHub Discussions](https://github.com/git-for-windows/git/discussions/). If, for some reason or other, you prefer a mailing list, use [the Git mailing list](mailto:[email protected]). It is actually a Google Group which can be used as if it were a forum, too.
 
 ## But I really have only a quick question!
 
-There is a [chat room](https://gitter.im/git-for-windows/git).
+Ask away [on Discord](https://discord.gg/GRFVkzgxRd).
 
 ## But I would prefer to email somebody directly!
 
-Please keep in mind that the time of competent Open Sourcerers is better spent on communicating publicly.
+Please keep in mind that the time of competent Open Sourcerers is better spent on communicating publicly.

How-to-participate.md

@@ -2,7 +2,7 @@ There are several ways to participate in the Git for Windows project. First off,
 
 # Help users
 
-On [the mailing list](http://groups.google.com/group/git-for-windows) or on [the issue tracker](https://github.com/git-for-windows/git/issues), help is always welcome.
+In [Git for Windows' discussions](https://github.com/git-for-windows/git/discussions/) or on [the issue tracker](https://github.com/git-for-windows/git/issues), help is always welcome.
 
 # Add documentation
 

Release-Hashes.md

@@ -1,5 +1,5 @@
 Release hashes are detailed in:
-*  the ANNOUNCE mail notifications on the <git[email protected]> list and
+*  the ANNOUNCE mail notifications on [the Git mailing list](mailto:git@vger.kernel.org) and
 *  on the https://github.com/git-for-windows/git/releases page.
 
-The list can be read and joined at https://groups.google.com/forum/#!forum/git-for-windows
+The list can be read at https://lore.kernel.org/git/ and joined [here](git[email protected]).

Releasing-Git-for-Windows.md

@@ -15,9 +15,8 @@ Note: the hardest part is traditonally preparing `-rc0` of every major release.
 There are essentially three-and-a-half venues where Git for Windows bugs are reported:
 
 - The Git for Windows bug tracker at https://github.com/git-for-windows/git/issues
-- The Git for Windows mailing list at https://groups.google.com/forum/#!forum/git-for-windows
-- The Git mailing list at https://public-inbox.org/git/
-- Twitter. Yep: ugh. Git for Windows is actually that popular that a couple of its users seriously think that Twitter would make for a perfectly fine way to report bugs. As if 280 characters were enough to make for a good bug report. Therefore, sometimes, when the Git for Windows maintainer feels particularly masochistic, they go to https://twitter.com/search?q=%23git-for-windows and see whether there is any valid bug report (one really has to pick out the needles between all that hay).
+- The Git mailing list at https://lore.kernel.org/git/
+- [Bluesky](https://bsky.app/search?q=git-for-windows).
 
 ## In case last-minute component updates are needed