Add .github/ISSUE_TEMPLATE/config.yml

- Disable blank (without using a template) issue
- Add a contact link to the support room on Matrix

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,6 @@
+---
+blank_issues_enabled: false
+contact_links:
+    - name: Support room on Matrix
+      url: https://matrix.to/#/#matrix-docker-ansible-deploy:devture.com
+      about: Get timely support from more people by joining our Matrix room.