chore: add release template for standardized release notes

Author: tonyHu08

.github/release-template.md

@@ -0,0 +1,30 @@
+## Summary
+
+- What changed in this release (high level)
+
+## Highlights
+
+1. Feature:
+2. Improvement:
+3. Fix:
+
+## Upgrade Notes
+
+1. Desktop users:
+2. Self-host users:
+
+## Screenshots / Demo
+
+- Screenshot 1:
+- Screenshot 2:
+- Screenshot 3:
+
+## Known Issues
+
+- Issue 1:
+- Issue 2:
+
+## Checks
+
+- [ ] `npm run typecheck`
+- [ ] `npm run build`