feat: improve PR description

.github/workflows/sync-rest-api-docs.yaml

@@ -41,7 +41,23 @@ jobs:
           token: "${{ secrets.GITHUB_TOKEN }}"
           path: docs
           title: Update camunda REST API doc
-          body: This PR updates the camunda REST API
+          body: |
+            ## Description
+
+            This is an autogenerated PR by the [sync api specs workflow](https://github.com/camunda/camunda-docs/tree/main/.github/workflows/sync-rest-api-docs.yaml).
+            This PR contains every changes made to the REST api specs in the [monorepo](https://github.com/camunda/camunda/blob/main/zeebe/gateway-protocol/src/main/proto/rest-api.yaml) in the last week.
+            This PR contains also all the generated OpenAPI files related to the changes.
+
+            ## When should this change go live?
+
+            - There is **no urgency** with this change and can be released at any time.
+
+            ## PR Checklist
+
+            - My changes are for the **next minor** and are in `/docs` directory (aka `/next/`).
+
+            - My changes require a [technical writer review](https://github.com/camunda/camunda-docs/blob/main/howtos/documentation-guidelines.md#review-process), and I've assigned @camunda/tech-writers as a reviewer.
+
           commit-message: "docs: update REST API spec"
           branch: update-rest-doc
           delete-branch: true