docs: introduce why-playwright.md (microsoft#3666)

Author: arjunattam

docs/README.md

@@ -18,6 +18,7 @@ Playwright is a library to automate [Chromium](https://www.chromium.org/Home), [
 ### Table of contents
 
 1. Introduction
+    - [Why Playwright?](./why-playwright.md)
     - [Getting started](./intro.md)
     - [First script](./intro.md#first-script)
     - [Core concepts](./core-concepts.md)

docs/why-playwright.md

@@ -0,0 +1,48 @@
+# Why Playwright?
+
+Playwright enables fast, reliable and capable automation across all modern browsers. This guide covers those key differentiators to help you decide on the right tool for your automated tests.
+
+<!-- GEN:toc-top-level -->
+- [Support for all browsers](#support-for-all-browsers)
+- [Fast and reliable execution](#fast-and-reliable-execution)
+- [Powerful automation capabilities](#powerful-automation-capabilities)
+- [Integrates with your workflow](#integrates-with-your-workflow)
+<!-- GEN:stop -->
+
+## Support for all browsers
+* **Test on Chromium, Firefox and WebKit**. Playwright has full API coverage for all modern browsers, including Google Chrome and Microsoft Edge (with [Chromium](https://www.chromium.org/)), Apple Safari (with [WebKit](https://webkit.org/)) and Mozilla Firefox.
+
+* **Cross-platform WebKit testing**. With Playwright, test how your app behaves in Apple Safari with WebKit builds for Windows, Linux and macOS. Test locally and on CI.
+
+* **Test for mobile**. Use [device emulation](emulation.md) to test your responsive web apps in mobile web browsers.
+
+* **Headless and headful**. Headless and headful automation is supported across all browsers and on all platforms.
+
+## Fast and reliable execution
+* **Auto-wait APIs**. Playwright interactions [auto-wait for elements](actionability.md) to be ready. This improves reliability and simplifies test authoring.
+
+* **Timeout-free automation**. Playwright receives browser signals, like network requests, page navigations and page load events to eliminate the need for sleep timeouts that cause flakiness.
+
+* **Lean parallelization with browser contexts**. Reuse a single browser instance for multiple parallelized, isolated execution environments with [browser contexts](core-concepts.md).
+
+* **Resilient element selectors**. Playwright can rely on user-facing strings, like text content and accessibility labels to [select elements](selectors.md). These strings are more resilient than selectors tightly-coupled to the DOM structure.
+
+## Powerful automation capabilities
+* **Multiple domains, pages and frames**. Playwright is an out-of-process automation driver that is not limited by the scope of in-page JavaScript execution and can automate scenarios with [multiple pages](multi-pages.md).
+
+* **Powerful network control**. Playwright introduces context-wide [network interception](network.md) to stub and mock network requests.
+
+* **Modern web features**. Playwright supports web components through [shadow-piercing selectors](selectors.md), [geolocation, permissions](emulation.md), web workers and other modern web APIs. 
+
+* **Capabilities to cover all scenarios**. Support for [file downloads](network.md) and [uploads](input.md), native [input events](input.md), and even [dark mode](emulation.md).
+
+## Integrates with your workflow
+* **One-line installation**. Running `npm i playwright` auto-downloads browser dependencies for your team to be onboarded quickly.
+
+* **TypeScript support**. Playwright ships with built-in types for auto-completion and other benefits.
+
+* **Debugging tools**. Playwright integrates with the [editor debugger](debug.md) to 
+
+* **Language bindings**. Playwright is also available in [Python](https://github.com/microsoft/playwright-python) and [C#](https://github.com/hardkoded/playwright-sharp).
+
+* **Deploy tests to CI**. First-party [Docker image](docker/README.md) and [GitHub Actions](https://github.com/microsoft/playwright-github-action) to deploy tests to [your preferred CI/CD provider](ci.md).