docs(playwright): a word about sharding

packages/playwright/docs/index.mdx

@@ -146,6 +146,10 @@ export default defineConfig({
 });
 ```
 
+## Sharding
+
+Argos seamlessly integrates with [Playwright test sharding](https://playwright.dev/docs/test-sharding), enabling efficient test distribution without the need for manual configuration. [Argos Sharding/Parallel mode](https://argos-ci.com/docs/parallel-testing) is automatically configured for you.
+
 ## Helper Attributes for Visual Testing
 
 For tailored visual testing, the `data-visual-test` attributes provide control over how elements appear in Argos screenshots. This can be especially useful for obscuring or modifying elements with dynamic content, like dates.