Update README.md

Author: JeeveshJ7

README.md

@@ -1,2 +1,52 @@
 # smartui-playwright-sample
-Playwright sample for running visual regression tests using SmartUI 
+# LambdaTest SmartUI Playwright Sample
+
+This project demonstrates how to use playwright and LambdaTest together to run automated tests on the LambdaTest platform.
+
+## Setup
+
+First, clone this repository to your local machine.
+
+```bash
+git clone https://github.com/LambdaTest/smartui-playwright-sample.git
+cd smartui-playwright-sample
+```
+
+Next, install the necessary dependencies:
+
+```bash
+npm i
+```
+
+You'll need to set your LambdaTest username and access key as environment variables. They can be found on your LambdaTest profile.
+
+```bash
+export LT_USERNAME="Your LambdaTest Username"
+export LT_ACCESS_KEY="Your LambdaTest Access Key"
+```
+
+## About the Test
+
+The test navigates to the LambdaTest homepage and checks the page title. After the title check, it will take a full-page screenshot for visual regression testing.
+
+## About SmartUI Webhook
+
+LambdaTest's SmartUI uses a webhook to call the `smartui.takeScreenshot` function. This function captures a screenshot of the full page and uses it for visual regression testing. The function is called using the `page.evaluate` method with the `lambdatest_action` parameter.
+
+Here's an example of how to use the `smartui.takeScreenshot` function:
+
+```javascript
+await page.evaluate((_) => {},
+    `lambdatest_action: ${JSON.stringify({ action: 'smartui.takeScreenshot', arguments: { fullPage: true, screenshotName: '<Your_Screenshot_Name>' }
+    })}`)
+```
+
+Replace `<Your Screenshot Name>` with a relevant name for the screenshot. The screenshot will be saved with this name in the LambdaTest platform, and you can use it for comparing the UI changes over time.
+
+## Running Tests
+
+To run the test, execute:
+
+```bash
+node playwright-smartui.js
+```