Fix markdown validation issues

Author: Philipp Alferov

readme.md

@@ -1,4 +1,5 @@
 # array-to-tree
+
 [![Build Status][travis-image]][travis-url] [![Dependency Status][depstat-image]][depstat-url]
 
 ![array-to-tree](media/array-to-tree.png)
@@ -9,31 +10,37 @@ Solves a problem with conversion of retrieved from a database sets of data to a
 
 ## Installation
 
-```
+```bash
 $ npm install array-to-tree --save
 ```
 
 ## Usage
+
 ```js
 var arrayToTree = require('array-to-tree');
 
-var dataOne = [{
-  id: 1,
-  name: "Portfolio",
-  parent_id: undefined
-}, {
-  id: 2,
-  name: "Web Development",
-  parent_id: 1
-}, {
-  id: 3,
-  name: "Recent Works",
-  parent_id: 2
-}, {
-  id: 4,
-  name: "About Me",
-  parent_id: undefined
-}];
+var dataOne = [
+  {
+    id: 1,
+    name: 'Portfolio',
+    parent_id: undefined
+  },
+  {
+    id: 2,
+    name: 'Web Development',
+    parent_id: 1
+  },
+  {
+    id: 3,
+    name: 'Recent Works',
+    parent_id: 2
+  },
+  {
+    id: 4,
+    name: 'About Me',
+    parent_id: undefined
+  }
+];
 
 arrayToTree(dataOne);
 
@@ -46,23 +53,28 @@ arrayToTree(dataOne);
  * About Me
  */
 
-var dataTwo = [{
-  _id: 'ec654ec1-7f8f-11e3-ae96-b385f4bc450c',
-  name: "Portfolio",
-  parent: null
-}, {
-  _id: 'ec666030-7f8f-11e3-ae96-0123456789ab',
-  name: "Web Development",
-  parent: 'ec654ec1-7f8f-11e3-ae96-b385f4bc450c'
-}, {
-  _id: 'ec66fc70-7f8f-11e3-ae96-000000000000',
-  name: "Recent Works",
-  parent: 'ec666030-7f8f-11e3-ae96-0123456789ab'
-}, {
-  _id: '32a4fbed-676d-47f9-a321-cb2f267e2918',
-  name: "About Me",
-  parent: null
-}];
+var dataTwo = [
+  {
+    _id: 'ec654ec1-7f8f-11e3-ae96-b385f4bc450c',
+    name: 'Portfolio',
+    parent: null
+  },
+  {
+    _id: 'ec666030-7f8f-11e3-ae96-0123456789ab',
+    name: 'Web Development',
+    parent: 'ec654ec1-7f8f-11e3-ae96-b385f4bc450c'
+  },
+  {
+    _id: 'ec66fc70-7f8f-11e3-ae96-000000000000',
+    name: 'Recent Works',
+    parent: 'ec666030-7f8f-11e3-ae96-0123456789ab'
+  },
+  {
+    _id: '32a4fbed-676d-47f9-a321-cb2f267e2918',
+    name: 'About Me',
+    parent: null
+  }
+];
 
 arrayToTree(dataTwo, {
   parentProperty: 'parent',
@@ -80,16 +92,20 @@ arrayToTree(dataTwo, {
 ```
 
 ## API
+
 ### `arrayToTree(data, [options])`
+
 Convert a plain array of nodes (with pointers to parent nodes) to a a nested data structure.
 
 #### Parameters
+
 - **Array** `data`: An array of data
 - **Object** `options`: An object containing the following fields:
   - `parentProperty` (String): A name of a property where a link to a parent node could be found. Default: 'parent_id'
   - `customID` (String): An unique node identifier. Default: 'id'
 
 #### Return
+
 - **Array**: Result of transformation
 
 ## License
@@ -98,6 +114,5 @@ MIT © [Philipp Alferov](https://github.com/alferov)
 
 [travis-url]: https://travis-ci.org/alferov/array-to-tree
 [travis-image]: https://img.shields.io/travis/alferov/array-to-tree.svg?style=flat-square
-
 [depstat-url]: https://david-dm.org/alferov/array-to-tree
 [depstat-image]: https://david-dm.org/alferov/array-to-tree.svg?style=flat-square