docs: add install / usage example to readme

Author: vladholubiev

README.md

@@ -1,2 +1,37 @@
-# elasticsearch-local
-Run any version of ElasticSearch locally
+# elasticsearch-local [![CircleCI](https://circleci.com/gh/shelfio/elasticsearch-local/tree/master.svg?style=svg)](https://circleci.com/gh/shelfio/elasticsearch-local/tree/master) ![](https://img.shields.io/badge/code_style-prettier-ff69b4.svg) [![npm (scoped)](https://img.shields.io/npm/v/@shelf/elasticsearch-local.svg)](https://www.npmjs.com/package/@shelf/elasticsearch-local)
+
+> Run any version of ElasticSearch locally
+
+## Usage
+
+### 0. Install
+
+```
+$ yarn add @shelf/elasticsearch-local --dev
+```
+
+### 1. Start Elasticsearch
+
+```js
+import {start} from '@shelf/elasticsearch-local';
+
+await start({
+  esVersion: '7.3.0',
+  port: 9000, // optional
+  clusterName: 'test', // optional
+  nodeName: 'test', // optional
+  indexes: ['one', 'two'] // optional
+});
+```
+
+### 2. Stop Elasticsearch
+
+```js
+import {stop} from '@shelf/elasticsearch-local';
+
+await stop();
+```
+
+## License
+
+MIT © [Shelf](https://shelf.io)