Update and rename feature_request.yml to feature_request.md

Author: pavelfeldman

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,11 @@
+---
+name: Feature request
+about: Request new features to be added
+title: "[Feature]"
+labels: ''
+assignees: ''
+
+---
+
+Let us know what functionality you'd like to see in Playwright and what your use case is.
+Do you think others might benefit from this as well?