docs(issue-template): add config.yml contact link for GitHub Discussions and update subtitle

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: tommysitu

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Questions about Hoverfly
+    url: https://github.com/SpectoLabs/hoverfly/discussions/new?category=q-a
+    about: Please ask questions and get support via GitHub Discussions

.github/ISSUE_TEMPLATE/question-about-Hoverfly.md

@@ -1,6 +1,6 @@
 ---
 name: Questions about Hoverfly
-about: This is not the appropriate channel - please use our Gitter channel
+about: This is not the appropriate channel - please create a GitHub Discussion
 
 ---