GitHub: Switch to new issue template system (#3862)

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,23 @@
+---
+name: "💡 Feature Request"
+about: Request a new feature
+title: ''
+labels: 'Feature Request'
+assignees: ''
+
+---
+
+<!--
+Please search the issue tracker for similar issues before posting!
+If your request is related to another request (but not the same!) list it here
+-->
+**Similar Requests**
+
+
+<!-- Describe your feature idea here in detail -->
+**Description of New Feature**
+
+
+<!-- If your feature requires some context, provide it here -->
+**Additional Context**
+