docs: add README for adev site (#55578)

PR Close #55578

README.md

@@ -63,22 +63,7 @@ Get started with Angular, learn the fundamentals and explore advanced topics on
 
 ### Local Development
 
-To contribute to Angular docs, you can setup a local environment with the following commands:
-
-```bash
-# Clone Angular repo
-git clone https://github.com/angular/angular.git
-
-# Navigate to project directory
-cd angular
-
-# Install dependencies
-yarn
-
-# Build and run local dev server
-# Note: Initial build will take some time
-yarn docs
-```
+To contribute to the Angular Docs, check out the [Angular.dev README](adev/README.md)
 
 ## Development Setup
 

adev/README.md

@@ -0,0 +1,37 @@
+# [Angular.dev](https://www.angular.dev)
+
+This site is built with Angular.
+
+The content is written primarly in Markdown format located in `src/content`. For simple edits, you can directly edit the file on GitHub and generate a Pull Request.
+
+## Local Development
+
+For local development, [yarn](https://yarnpkg.com/) is the preferred package manager. You can setup a local environment with the following commands
+:
+
+```bash
+# Clone Angular repo
+git clone https://github.com/angular/angular.git
+
+# Navigate to project directory
+cd angular
+
+# Install dependencies
+yarn
+
+# Build and run local dev server
+# Note: Initial build will take some time
+yarn docs
+```
+
+## Contributing
+
+Want to report a bug, contribute some code, or improve the documentation? Excellent!
+
+Read through our [contributing guidelines](CONTRIBUTING.md) to learn about our submission process, coding rules, and more.
+
+And if you're new, check out one of our issues labeled as <kbd>[help wanted](https://github.com/angular/angular/labels/help%20wanted)</kbd> or <kbd>[good first issue](https://github.com/angular/angular/labels/good%20first%20issue)</kbd>.
+
+### Code of Conduct
+
+Help us keep Angular open and inclusive. Please read and follow our [Code of Conduct](CODE_OF_CONDUCT.md).