Update action.md with alternative bot trigger

action.md

@@ -6,7 +6,11 @@ First thing you'd need to do is create an OPENAI_API_KEY secret in github, more
 
 Once you've set your secret you can create a new file in your workflow called crgpt.yml, which should look like something seen below. An important attribute to include, is the fetch-depth of the checkout action below. Currently the action only works when it has access to the repo's entire commit history.
 
-```shell
+### Workflow yml option 1: Review every PR
+
+Trigger a code review on any PR into main, updating it each time you push changes.
+
+```yaml
 name: Code Review GPT
 
 on:
@@ -27,4 +31,36 @@ jobs:
           OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
           MODEL: 'gpt-4o'
           GITHUB_TOKEN: ${{ github.token }}
-```
+```
+
+### Workflow yml option 2: Add a code review bot
+
+In this config, a GPT CR is triggered when a specific user is added as a "reviewer" in the Github UI. Create an additional Github account such as 'YourProject-ML-CR-bot', then specify the account username in the config.
+
+This option can save on API costs by only reviewing when explicity asked to. It can also be used to avoid reviewing PRs before they are ready (draft/WIP PRs).
+
+To trigger a re-review, simply remove and re-add the bot to the reviewers list.
+
+```yaml
+name: Code Review GPT
+
+on:
+  pull_request:
+    types: [ review_requested ]
+
+jobs:
+  run_code_review:
+    if: ${{ github.event.requested_reviewer.login == 'YourProject-ML-CR-bot'}}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Code Review GPT
+        uses: mattzcarey/[email protected]
+        with:
+          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
+          MODEL: 'gpt-4o'
+          GITHUB_TOKEN: ${{ github.token }}
+```