add docs

README.md

@@ -0,0 +1,83 @@
+# [is-async-function][author-www-url] [![npmjs.com][npmjs-img]][npmjs-url] [![The MIT License][license-img]][license-url] 
+
+> Is function really asynchronous (callback) function? Trying to guess that based on check if `callback`, `cb`, `done`, `next` exists as function argument names - or you can pass you custom.
+
+[![code climate][codeclimate-img]][codeclimate-url] [![standard code style][standard-img]][standard-url] [![travis build status][travis-img]][travis-url] [![coverage status][coveralls-img]][coveralls-url] [![dependency status][david-img]][david-url]
+
+## Install
+```
+npm i is-async-function --save
+```
+
+## Usage
+> For more use-cases see the [tests](./test.js)
+
+```js
+const isAsyncFunction = require('is-async-function')
+```
+
+### [isAsyncFn](index.js#L20)
+
+> Trying to guess is function asynchronous (callback) function or not.
+
+**Params**
+
+* `fn` **{Function}**    
+* `ignores` **{Array}**    
+* `max` **{Number}**    
+* `returns` **{Boolean}**  
+
+## Contributing
+Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/tunnckoCore/is-async-function/issues/new).  
+But before doing anything, please read the [CONTRIBUTING.md](./CONTRIBUTING.md) guidelines.
+
+## [Charlike Make Reagent](http://j.mp/1stW47C) [![new message to charlike][new-message-img]][new-message-url] [![freenode #charlike][freenode-img]][freenode-url]
+
+[![tunnckoCore.tk][author-www-img]][author-www-url] [![keybase tunnckoCore][keybase-img]][keybase-url] [![tunnckoCore npm][author-npm-img]][author-npm-url] [![tunnckoCore twitter][author-twitter-img]][author-twitter-url] [![tunnckoCore github][author-github-img]][author-github-url]
+
+[arr-includes]: https://github.com/tunnckocore/arr-includes
+[function-arguments]: https://github.com/tunnckocore/function-arguments
+[isarray]: https://github.com/juliangruber/isarray
+
+[npmjs-url]: https://www.npmjs.com/package/is-async-function
+[npmjs-img]: https://img.shields.io/npm/v/is-async-function.svg?label=is-async-function
+
+[license-url]: https://github.com/tunnckoCore/is-async-function/blob/master/LICENSE
+[license-img]: https://img.shields.io/badge/license-MIT-blue.svg
+
+[codeclimate-url]: https://codeclimate.com/github/tunnckoCore/is-async-function
+[codeclimate-img]: https://img.shields.io/codeclimate/github/tunnckoCore/is-async-function.svg
+
+[travis-url]: https://travis-ci.org/tunnckoCore/is-async-function
+[travis-img]: https://img.shields.io/travis/tunnckoCore/is-async-function/master.svg
+
+[coveralls-url]: https://coveralls.io/r/tunnckoCore/is-async-function
+[coveralls-img]: https://img.shields.io/coveralls/tunnckoCore/is-async-function.svg
+
+[david-url]: https://david-dm.org/tunnckoCore/is-async-function
+[david-img]: https://img.shields.io/david/tunnckoCore/is-async-function.svg
+
+[standard-url]: https://github.com/feross/standard
+[standard-img]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg
+
+[author-www-url]: http://www.tunnckocore.tk
+[author-www-img]: https://img.shields.io/badge/www-tunnckocore.tk-fe7d37.svg
+
+[keybase-url]: https://keybase.io/tunnckocore
+[keybase-img]: https://img.shields.io/badge/keybase-tunnckocore-8a7967.svg
+
+[author-npm-url]: https://www.npmjs.com/~tunnckocore
+[author-npm-img]: https://img.shields.io/badge/npm-~tunnckocore-cb3837.svg
+
+[author-twitter-url]: https://twitter.com/tunnckoCore
+[author-twitter-img]: https://img.shields.io/badge/twitter-@tunnckoCore-55acee.svg
+
+[author-github-url]: https://github.com/tunnckoCore
+[author-github-img]: https://img.shields.io/badge/github-@tunnckoCore-4183c4.svg
+
+[freenode-url]: http://webchat.freenode.net/?channels=charlike
+[freenode-img]: https://img.shields.io/badge/freenode-%23charlike-5654a4.svg
+
+[new-message-url]: https://github.com/tunnckoCore/ama
+[new-message-img]: https://img.shields.io/badge/ask%20me-anything-green.svg
+