feat: add link to discourse forum (ublue-os#658)

* feat: add link to discourse forum

* fix: change forum link

mkdocs.yml

@@ -66,6 +66,8 @@ extra:
     provider: google
     property: G-QJBLY50M60
   social:
+    - icon: fontawesome/brands/discourse
+      link: https://universal-blue.discourse.group
     - icon: fontawesome/brands/discord
       link: https://discord.gg/WEu6BdFEtp
     - icon: fontawesome/brands/youtube
@@ -117,7 +119,7 @@ nav:
       - Code of Conduct: CODE_OF_CONDUCT.md
       - Membership: membership.md
       - Discord Chat: https://discord.gg/WEu6BdFEtp
-      - Discussion Forums: https://github.com/orgs/ublue-os/discussions
+      - Discussion Forums: https://universal-blue.discourse.group/
       - Videos: https://www.youtube.com/c/JorgeCastro/videos
   - Documentation:
       - Introduction: introduction.md