add Chore and Feature issue templates (#760)

* add Chore template

from mozilla-mobile/firefox-tv

* add Feature template

* Rename --chore.md to ---chore.md

* Move PR template to be with other GitHub-specific docs

Author: devinreams

.github/ISSUE_TEMPLATE/---chore.md

@@ -0,0 +1,12 @@
+---
+name: "🧶 Chore"
+about: Tech debt, developer ergonomics, tooling, etc.
+labels: "chore"
+
+---
+
+### Vision statement / What / Requirements
+
+### Impact
+
+### Acceptance criteria

.github/ISSUE_TEMPLATE/---feature.md

@@ -0,0 +1,12 @@
+---
+name: "⭐️ Feature request"
+about: Suggest an idea for this project
+labels: "feature"
+
+---
+
+### Why/User Benefit/User Problem
+
+### Acceptance Criteria (how do I know when I’m done?)
+
+### Not included