REUSE-compliant licensing

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,5 +1,5 @@
 name: I think I found a bug
-description: File a bug report issue
+description: File a bug report issue. If you have a question or are experiencing a problem, please start a [new discussion](https://github.com/stalwartlabs/mail-server/discussions/new?category=q-a) instead.
 title: "[bug]: "
 labels: ["bug"]
 body:
@@ -33,8 +33,7 @@ body:
       options:
         - v0.8.x
         - v0.7.x
-        - v0.6.x
-        - v0.5.x or lower
+        - v0.6.x or lower
     validations:
       required: true
   - type: dropdown

.github/ISSUE_TEMPLATE/config.yml

@@ -9,3 +9,6 @@ contact_links:
   - name: Join Stalwart's Discord
     url: https://discord.gg/aVQr3jF8jd
     about: Join our Discord server for help, discussions and release announcements.
+  - name: Join Stalwart's Matrix
+    url: https://matrix.to/#/#stalwart:matrix.org
+    about: Join our Matrix room for help, discussions and release announcements.