ci: add release.yml for categorized release notes

Groups auto-generated release notes by label: Breaking / Features /
Bug Fixes / Documentation / Dependencies / Other. Excludes
duplicate/invalid/wontfix from notes.

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:
+        - "*"