Docs: Add a proper README

Author: phated

README.md

@@ -1,2 +1,40 @@
-# identity-map
+# @gulp-sourcemaps/identity-map
+
+[![NPM version][npm-image]][npm-url] [![Downloads][downloads-image]][npm-url] [![Build Status][travis-image]][travis-url] [![AppVeyor Build Status][appveyor-image]][appveyor-url] [![Coveralls Status][coveralls-image]][coveralls-url]
+
 Gulp plugin for generating an identity sourcemap for a file.
+
+## Example
+
+```js
+var identityMap = require('@gulp-sourcemaps/identity-map');
+
+gulp.src(...)
+  .pipe(sourcemaps.init())
+  .pipe(identityMap()) // .js and .css files will get a generated sourcemap
+  .pipe(sourcemaps.write())
+  .pipe(gulp.dest(...))
+```
+
+## API
+
+### `identityMap()`
+
+Returns an `objectMode` Transform stream that processes each file with a `.sourceMap` property and buffered contents. A sourcemap is generated and attached for each `.js` and `.css` file.
+
+## License
+
+MIT
+
+[downloads-image]: http://img.shields.io/npm/dm/@gulp-sourcemaps/identity-map.svg
+[npm-url]: https://npmjs.org/package/@gulp-sourcemaps/identity-map
+[npm-image]: http://img.shields.io/npm/v/@gulp-sourcemaps/identity-map.svg
+
+[travis-url]: https://travis-ci.org/gulp-sourcemaps/identity-map
+[travis-image]: http://img.shields.io/travis/gulp-sourcemaps/identity-map.svg?label=travis-ci
+
+[appveyor-url]: https://ci.appveyor.com/project/phated/identity-map
+[appveyor-image]: https://img.shields.io/appveyor/ci/phated/identity-map.svg?label=appveyor
+
+[coveralls-url]: https://coveralls.io/r/gulp-sourcemaps/identity-map
+[coveralls-image]: http://img.shields.io/coveralls/gulp-sourcemaps/identity-map.svg