Update readme

Author: teabyii

README.md

@@ -1,2 +1,62 @@
-# JavaScript
-JavaScript implementation of SRL.
+# SRL-JavaScript
+
+JavaScript implementation of [Simple Regex](https://simple-regex.com/) :tada::tada::tada:
+
+[![npm version](https://badge.fury.io/js/srl.svg)](https://badge.fury.io/js/srl)
+[![Build Status](https://travis-ci.org/SimpleRegex/SRL-JavaScript.svg?branch=master)](https://travis-ci.org/SimpleRegex/SRL-JavaScript)
+[![codecov](https://codecov.io/gh/SimpleRegex/SRL-JavaScript/branch/master/graph/badge.svg)](https://codecov.io/gh/SimpleRegex/SRL-JavaScript)
+
+> Because of the JavaScript regex engine, there is something different from [Simple Regex](https://simple-regex.com/) 
+- NOT support `as` to assign capture name. 
+- NOT support `if already had/if not already had` 
+- NO `firstMatch`, since in JavaScript `lazy` means non-greedy (matching the fewest possible characters).
+
+## Installation
+
+```sh
+npm install srl
+```
+
+## Usage
+
+Class SRL accepts a Simple Regex Language string as input, and return the builder for the query. 
+
+The builder can agent `test/exec` method to the generated regex object. Or you can use `get()` to take the generated regex object.
+
+```js
+const SRL = require('srl')
+const query = new SRL('letter exactly 3 times')
+const regex = query.get() // /[a-z]{3}/
+
+query.test('aaa') // true
+query.exec('aaa') // [ 'aaa', index: 0, input: 'aaa' ]
+
+query
+    .digit()
+    .neverOrMore()
+    .mustEnd()
+    .get() // /[a-z]{3}[0-9]*$/
+```
+
+Required Node 6.0+ for the ES6 support, Or you can use [Babel](http://babeljs.io/) to support Node below 6.0.
+
+Using [Webpack](http://webpack.github.io) and [babel-loader](https://github.com/babel/babel-loader) to pack it if want to use in browsers. 
+
+## Development
+
+First, clone repo and init submodule for test.
+
+SRL-JavaScript depends on [Mocha](http://mochajs.org) and [Istanbul](https://github.com/gotwarlost/istanbul) to test code. You can use them like this:
+
+```sh
+npm install
+
+npm test # test 
+npm run coverage # Get coverage locally 
+```
+
+How to write Rules, see: [Test-Rules](https://github.com/SimpleRegex/Test-Rules).
+
+## License
+
+SRL-JavaScript is published under the MIT license. See LICENSE for more information.