Merge pull request #2035 from ClickHouse/enhancement-request-template

[repo] Add a template for enhancement request

Author: mshustov

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: Suggest an idea for the package
+title: ''
+labels: enhancement
+assignees: ''
+
+---
+
+<!-- delete unnecessary items -->
+### Use case
+
+### Describe the solution you'd like
+
+### Describe the alternatives you've considered
+
+### Additional context