ci: add release.yml for categorized release notes (#28)

Adds .github/release.yml so gh release create --generate-notes (and the GitHub UI auto-generator) groups PRs by label instead of producing a flat commit list. Categories: Breaking Changes, Features, Bug Fixes, Documentation, Dependencies, Other Changes. Excludes duplicate/invalid/wontfix. Refs opendecree/decree#145.

Author: zeevdr

.github/release.yml

@@ -0,0 +1,26 @@
+changelog:
+  exclude:
+    labels:
+      - duplicate
+      - invalid
+      - wontfix
+  categories:
+    - title: "⚠️ Breaking Changes"
+      labels:
+        - breaking
+    - title: "Features"
+      labels:
+        - enhancement
+    - title: "Bug Fixes"
+      labels:
+        - bug
+    - title: "Documentation"
+      labels:
+        - docs
+        - documentation
+    - title: "Dependencies"
+      labels:
+        - dependencies
+    - title: "Other Changes"
+      labels:
+        - "*"