Merge pull request #9 from aniruddha2000/flatcar-master

Doc: Update the IRC link from freenode to libera

CONTRIBUTING.md

@@ -14,9 +14,8 @@ contribution. See the [DCO](DCO) file for details.
 
 # Email and Chat
 
-The project currently uses the general Flatcar email list and IRC channel:
-- Email: [flatcar-user](https://groups.google.com/g/flatcar-linux-user)
-- IRC: #[flatcar](irc://irc.freenode.org:6667/#flatcar) IRC channel on freenode.org
+Read [Participate and contribute](https://github.com/kinvolk/flatcar#participate-and-contribute)
+for mailing list and matrix chat information.
 
 Please avoid emailing maintainers found in the MAINTAINERS file directly. They
 are very busy and read the mailing lists.