OpenAPI change reminder (#3138)

- Nudges author to think about backwards compatibility when openapi.yml
changes.
- Reminds to make DB migration revertable.

.github/nitpicks.yml

@@ -1,4 +1,13 @@
 - markdown: |
-    Reminder: Please update the DB Readme.
+    Reminder: Please update the DB Readme and comment whether migrations are reversible (include rollback scripts if applicable).
   pathFilter:
     - "database/sql/**"
+
+- markdown: |
+    Reminder: Please consider backward compatibility when modifying the API specification. 
+    If breaking changes are unavoidable, ensure:
+    - You explicitly pointed out breaking changes.
+    - You communicate the changes to affected teams.
+    - You provide proper versioning and migration mechanisms.
+  pathFilter:
+    - "**/openapi.yml"