Change: Update issue template to show link to our forum

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Greenbone Community Forum
+    url: https://forum.greenbone.net/
+    about: Please ask questions here.

.github/ISSUE_TEMPLATE/issue-report.md

@@ -0,0 +1,65 @@
+---
+name: Bug Report
+about: Report an issue
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+<!--
+If reporting an issue please try to provide the information asked below.
+
+Before reporting an issue please:
+
+1. Be aware that this is not a support forum. If your issue is rather a question
+   than a bug report, please use our community forum at
+   https://forum.greenbone.net/ instead.
+2. Make sure that you're using the latest published release
+3. Check the list of issues whether it isn't already reported.
+4. Read 1. again and if you still believe you found a software bug please
+   continue to file this issue. If you are in doubt use
+   https://forum.greenbone.net/ instead.
+
+Thanks for your help to keep the communication channels clean and consistent!
+-->
+
+### Expected behavior
+
+<!--
+  How did you expect the software to behave?
+  Please write down how it should work in your opinion.
+-->
+
+### Actual behavior
+
+<!--
+  Did something go wrong?
+  Is something broken, or not behaving as you expected?
+  Is this really an bug? If in doubt please use
+  https://forum.greenbone.net instead.
+-->
+
+### Steps to reproduce
+
+<!--
+  How would you describe your issue to someone who doesn’t know something about
+  this software? Try to write a sequence of steps that anybody can repeat to see
+  the issue.
+-->
+
+1.
+2.
+3.
+
+### Environment
+
+**Operating system:**
+
+**Installation method / source:** (packages, source installation)
+
+### Logfiles
+<!-- in most cases you'll find the logs in /var/log/gvm/ -->
+```
+
+```