Update support links

Author: hwittenborn

README.md

@@ -51,7 +51,11 @@ sudo apt install celeste
 ```
 
 ## Support
-For anything that isn't an issue in Celeste's functionality, visit the project's [Discord server](https://discord.gg/FtNhPepvj7), where you can obtain support and chat with fellow users. If you have a bug/feature request for Celeste, then make a new issue in the project's [issue tracker](https://github.com/hwittenborn/celeste/issues).
+Celeste has multiple communication rooms available if you need assistance, want to talk about the project, or to just hang around with some fellow users:
+- Discord: https://discord.gg/FtNhPepvj7
+- Matrix: https://matrix.to/#/#celeste:gnome.org
+
+**Bugs and features can be discussed in the rooms if you feel like there's information that should be talked about, but such should ultimately fall into the [issue tracker](https://github.com/hwittenborn/celeste/issues).**
 
 ## Contributing
 Instructions still largely need to be written up - if you'd like to help with that, feel free to submit a PR!