Add feature_request issue template

Author: CarlosNZ

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,14 @@
+---
+name: Feature request
+about: Request new features or enhancements
+title: Feature request
+labels: "user request"
+assignees: ''
+
+---
+
+**Suggestion**
+<!-- Describe the functionality you would like added. -->
+
+**Use case**
+<!-- Please provide examples of a use case where this would be a desirable feature -->