Update README.md

Author: colebemis

README.md

@@ -1,2 +1,29 @@
 # eslint-plugin-primer-react
 ESLint rules for Primer React
+
+## Installation
+
+1. Assuming you already have [ESLint](https://www.npmjs.com/package/eslint) installed, run:
+
+   ```shell
+   # npm 
+   npm install --save-dev eslint-plugin-primer-react
+ 
+   # yarn 
+   yarn add --dev eslint-plugin-primer-react
+   ```
+
+2. In your [ESLint configuration file](https://eslint.org/docs/user-guide/configuring/configuration-files), extend the recommended Primer React ESLint config:
+
+   ```js
+   {
+     "extends": [
+       // ...
+       "plugin:primer-react/recommended"
+     ]
+   }
+   ```
+
+## Rules
+
+* [no-deprecated-color-variables](#)