feat: add ai pr review docs

docs/contributing/pull-request-guidelines/.pages

@@ -1,5 +1,6 @@
 nav:
   - index.md
+  - ai-pr-review.md
   - ci-checks.md
   - code-owners.md
   - commit-guidelines.md

docs/contributing/pull-request-guidelines/ai-pr-review.md

@@ -0,0 +1,51 @@
+# AI PR Review
+
+We have [Codium-ai/pr-agent](https://github.com/Codium-ai/pr-agent/tree/main) enabled for Autoware Universe repository.
+
+## The workflow
+
+Workflow: [pr-agent.yaml](https://github.com/autowarefoundation/autoware.universe/blob/main/.github/workflows/pr-agent.yaml)
+
+### Additional links for the workflow maintainers
+
+- [Available models list](https://github.com/Codium-ai/pr-agent/blob/main/pr_agent/algo/__init__.py)
+
+## How to use
+
+When you create the PR, or within the PR add the label `tag:pr-agent`.
+
+Wait until both PR-Agent jobs are completed successfully:
+
+- `prevent-no-label-execution-pr-agent / prevent-no-label-execution`
+- `Run pr agent on every pull request, respond to user comments`
+
+!!! warning
+
+    If you add multiple labels at the same time, `prevent-no-label-execution` can get confused.
+
+    For example, first add `tag:pr-agent`, wait until it is ready, then add `tag:run-build-and-test-differential` if you need it.
+
+Then you can pick one of the following commands:
+
+```text
+/review: Request a review of your Pull Request.
+/describe: Update the PR description based on the contents of the PR.
+/improve: Suggest code improvements.
+/ask Could you propose a better name for this parameter?: Ask a question about the PR or anything really.
+/update_changelog: Update the changelog based on the PR's contents.
+/add_docs: Generate docstring for new components introduced in the PR.
+/help: Get a list of all available PR-Agent tools and their descriptions.
+```
+
+- [Here is the official documentation](https://pr-agent-docs.codium.ai/tools/).
+- [Usage Guide](https://pr-agent-docs.codium.ai/usage-guide/automations_and_usage/#online-usage)
+
+To use it, [drop a comment post within your PR like this](https://github.com/Codium-ai/pr-agent/pull/229#issuecomment-1695021901).
+
+Within a minute, you should see 👀 reaction under your comment post.
+
+Then the bot will drop a response with reviews, description or an answer.
+
+!!! info
+
+    Please drop a single PR-Agent related comment at a time.