github: add issue templates

.github/ISSUE_TEMPLATE/feature-request.md

@@ -0,0 +1,17 @@
+---
+name: feature request
+about: suggest a feature for cobalt
+title: ''
+labels: feature request
+assignees: ''
+
+---
+
+**describe the feature you'd like to see**
+a clear and concise description of what you want to happen.
+
+**describe alternatives you've considered**
+a clear and concise description of any alternative solutions or features you've considered.
+
+**additional context**
+add any other context or screenshots about the feature request here.