Merge branch 'add-irc-to-get-involved' into 'master'

Add IRC channel to get involved page

See merge request !40

content/page/get-involved.md

@@ -11,9 +11,12 @@ experienced contributors.
 
 If you're interested in getting involved or following the progress of
 the project, please [join the development mailing
-list](https://lists.sourceforge.net/lists/listinfo/briar-devel) or email
-{{<contactemail>}}. Translators
-can volunteer through our [Transifex
+list](https://lists.sourceforge.net/lists/listinfo/briar-devel)
+or email {{<contactemail>}}.
+You can also join our chat channel using
+[IRC](irc://chat.freenode.net/briar) (#briar on freenode) or
+[Matrix](https://matrix.to/#/#freenode_#briar:matrix.org).
+Translators can volunteer through our [Transifex
 project](https://transifex.com/otf/briar).
 
 All our software is open source - you can [browse the source