docs: add Trivy scan badges

| Input / Variable | Description                                                                                                                 | Default value                               |

| ------------------------ | --------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- |

| `image` / `PLAYWRIGHT_IMAGE` | The Docker image used to run Playwright.                                                                                    | `mcr.microsoft.com/playwright:latest` |

| `image` / `PLAYWRIGHT_IMAGE` | The Docker image used to run Playwright.                                                                                    | `mcr.microsoft.com/playwright:latest` <br/>[![Trivy Badge](https://to-be-continuous.gitlab.io/doc/secu/trivy-badge-PLAYWRIGHT_IMAGE.svg)](https://to-be-continuous.gitlab.io/doc/secu/trivy-PLAYWRIGHT_IMAGE) |

| `project-dir` / `PLAYWRIGHT_PROJECT_DIR` | The Playwright root project directory (contains the `playwright.config.ts` file)                                            | `.`                                         |

| `extra-args` / `PLAYWRIGHT_EXTRA_ARGS` | Playwright extra [run options](https://playwright.dev/docs/test-cli)                                                        | _none_                                      |

| `review-enabled` / `REVIEW_ENABLED` | Set to `true` to enable Playwright tests on review environments (dynamic environments instantiated on development branches) | _none_ (disabled)                           |