Add GitHub installed browsers

Author: MikeMcC399

docs/guides/continuous-integration/github-actions.mdx

@@ -129,6 +129,31 @@ example project and place the above GitHub Action configuration in
   - Start the project web server (`npm start`)
   - Run the Cypress tests within our GitHub repository within Electron.
 
+## Testing on GitHub with Installed Browsers
+
+[GitHub-hosted runners](https://github.com/actions/runner-images) offer images
+with pre-installed browsers to use for testing. The `ubuntu` and `windows`
+runners each include Google Chrome, Mozilla Firefox and Microsoft Edge
+pre-installed. The `macos` runners additionally include Apple Safari. Refer to
+[GitHub Actions Runner Images](https://github.com/actions/runner-images/blob/main/README.md)
+for current details.
+
+Use the action's `browser` parameter to select the desired browser. To change
+the above example to select Chrome instead of the default browser Electron, add
+`browser: chrome` as follows.
+
+```yaml
+- name: Cypress run
+  uses: cypress-io/github-action@v5
+  with:
+    build: npm run build
+    start: npm start
+    browser: chrome
+```
+
+For more examples, see the action's
+[Browser](https://github.com/cypress-io/github-action#browser) section.
+
 ## Testing in Chrome and Firefox with Cypress Docker Images
 
 GitHub Actions provides the option to specify a container image for the job.