Add babel-generator README

packages/babel-generator/README.md

@@ -1 +1,21 @@
 # babel-generator
+
+> Turns an AST into code.
+
+## Install
+
+```sh
+$ npm install babel-generator
+```
+
+## Usage
+
+```js
+import {parse} from 'babylon';
+import generate from 'babel-generator';
+
+const code = 'class Example {}';
+const ast = parse(ast);
+
+const output = generate(ast, { /* options */ }, code);
+```