add manual launch sample for nodejs (#199)

Author: puagarwa

samples/playwright-lib/ReadMe.md

@@ -0,0 +1,18 @@
+# Example Playwright Library Project with Service Workspace
+# How to use this example
+- Clone the repo and go to the folder
+- npm install
+- Create a Playwright workspace by following the [Getting Started guide](https://aka.ms/mpt/manage-workspaces)
+- Follow the [Getting Started guidance](https://aka.ms/mpt/configure-service-endpoint) and set the regional endpoint environment variable
+```
+$env:PLAYWRIGHT_SERVICE_URL="wss://...."
+```
+- Generate access token following [guide](https://aka.ms/mpt/generate-access-token)
+- Set the token generated in the previous step
+```
+$env:PLAYWRIGHT_SERVICE_ACCESS_TOKEN="TOKEN_VALUE"
+```
+- Run the example script
+```
+npx ts-node src/example.ts
+```