feature: add readme for api mocking (#7)

tests/api-mocking/readme.md

@@ -0,0 +1,25 @@
+---
+name: Playwright - API Mocking
+description: "This sample demonstrates how to mock API calls in Playwright tests"
+page_type: sample
+languages:
+- typescript
+- javascript
+products:
+- playwright
+urlFragment: api-mocking
+---
+
+# API Mocking
+
+This sample demonstrates how to 
+- mock API calls in Playwright tests
+- intercept the request and modifying it
+- mock using HAR files
+
+For more information about the sample see:
+
+- [Playwright API Mocking demo](https://demo.playwright.dev/api-mocking)
+- [Blog post on API Mocking](https://dev.to/playwright/api-mocking-for-your-playwright-tests-47ah)
+- [Docs on API Mocking](https://playwright.dev/docs/mock)
+- [Release video on our Network Annotations feature which gives you a clearer view of what your API call and fulfillments are doing](https://youtu.be/pJiirfyJwcA)