fix(docs): updates to readme and badges

Author: kwelch

README.md

@@ -1,24 +1,41 @@
 # Entities reducer
 
+Redux high order reducer for normalized `flux-standard-action`s  
+
 [![Build Status][build-badge]][build]
 [![Code Coverage][coverage-badge]][coverage]
 [![version][version-badge]][package]
 
 
 [![Watch on GitHub][github-watch-badge]][github-watch]
 [![Star on GitHub][github-star-badge]][github-star]
-[![Tweet][twitter-badge]][twitter]
 
 
--- TODO: Write some docs
+Allows for updates to entities in state. Accepts custom reducers to further control.
+
+## Usage
+
+```javascript
+import { combineReducers } from 'redux';
+import entitiesReducer from 'entities-reducer';
 
-For now read the tests :)
+const rootReducer = combineReducers({
+  entities: entitiesReducer({
+    /* custom reducers here */
+  }),
+});
 
+export default rootReducer;
+```
 
 
+[build]: https://travis-ci.org/kwelch/entities-reducer
 [build-badge]: https://img.shields.io/travis/kwelch/entities-reducer.svg?style=flat-square
 [coverage-badge]: https://img.shields.io/codecov/c/github/kwelch/entities-reducer.svg?style=flat-square
+[coverage]: https://codecov.io/github/kwelch/entities-reducer
 [github-watch-badge]: https://img.shields.io/github/watchers/kwelch/entities-reducer.svg?style=social
+[github-watch]: https://github.com/kwelch/entities-reducer/watchers
 [github-star-badge]: https://img.shields.io/github/stars/kwelch/entities-reducer.svg?style=social
-[twitter-badge]: https://img.shields.io/twitter/url/https/github.com/kwelch/entities-reducer.svg?style=social
+[github-star]: https://github.com/kwelch/entities-reducer/stargazers
 [version-badge]: https://img.shields.io/npm/v/entities-reducer.svg?style=flat-square
+[package]: https://www.npmjs.com/package/entities-reducer