Added link to Q&A to issue templates (#2834)

Author: RunDevelopment

Diff for: .github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,4 @@
+contact_links:
+    - name: Questions and Help
+      url: https://github.com/PrismJS/prism/discussions/categories/q-a
+      about: This issue tracker is not for support questions. Please refer to the Prism's Discussion tab.