Add links to community.mailpile.is

CONTRIBUTING.md

@@ -19,7 +19,8 @@ before filing issues about design choices or attempting to reorganize the code
 in any major way. The FAQ also contains a quick introduction Mailpile internals
 and debugging techniques.
 
-Also, have you seen [the main Mailpile website](https://www.mailpile.is/)?
+Also, have you seen [the main Mailpile website](https://www.mailpile.is/) and
+[the community Discourse](https://community.mailpile.is/categories)?
 
 
 #### Are you new to Mailpile and/or FOSS?
@@ -59,6 +60,9 @@ Also, have you seen [the main Mailpile website](https://www.mailpile.is/)?
 
 * The [Developer FAQ](DEV_FAQ.md) has a section on debugging techniques.
 
+* If it's not bug, but you still need help: [visit our Discourse support
+  forum](https://community.mailpile.is/c/support).
+
 
 #### Did you write a patch that fixes a bug?
 
@@ -94,6 +98,13 @@ patches and we would rather focus our efforts on functional improvements to the
 software.
 
 
+#### Do you want help other users?
+
+Our [community Discourse](https://community.mailpile.is/categories) has a
+support forum and needs friendly people to help out and steer conversations
+in friendly and productive directions. Please join the conversation!
+
+
 #### Do you want to translate Mailpile to your language?
 
 Please feel free to join our translation community