Add feature request template

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -0,0 +1,15 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+<!-- Before opening a new issue, please search for duplicate issues to prevent opening a duplicate feature request. If there is already an open existing request, please leave a comment there. -->
+
+## Is your feature request related to a problem? Please describe.
+
+## Describe the solution you'd like
+
+## Why do you think this feature is something we should consider for the Yoast SEO plugins?
+
+## Additional context