Add #borgmatic Freenode IRC channel to documentation.

NEWS

@@ -1,6 +1,7 @@
 1.3.6.dev0
  * #178: Look for .yml configuration file extension in addition to .yaml.
  * Remove Python cache files before each Tox run.
+ * Add #borgmatic Freenode IRC channel to documentation.
  * Add Borg/borgmatic hosting providers section to documentation.
 
 1.3.5

README.md

@@ -95,6 +95,11 @@ create a new issue or comment on an issue, you'll need to [login
 first](https://projects.torsion.org/user/login). Note that you can login with
 an existing GitHub account if you prefer.
 
+If you'd like to chat with borgmatic developers or users, head on over to the
+`#borgmatic` IRC channel on Freenode, either via <a
+href="https://webchat.freenode.net">web chat</a> or a native <a
+href="irc://chat.freenode.net:6697">IRC client</a>.
+
 Other questions or comments? Contact <mailto:witten@torsion.org>.