upd Readme

Author: voischev

README.md

@@ -5,6 +5,59 @@
 
 Parse HTML/XML to [PostHTMLTree](https://github.com/posthtml/posthtml#posthtml-json-tree-example)
 
+## Install
+
+[NPM](http://npmjs.com) install
+```
+$ npm install posthtml-parser
+```
+
+## Usage 
+
+#### input HTML
+```html
+<a class="animals" href="#">
+    <span class="animals__cat" style="background: url(cat.png)">Cat</span>
+</a>
+```
+```js
+var parser = require('posthtml-parser');
+var fs = require('fs');
+var html = fs.readFileSync('path/to/input.html').toString();
+
+clonsole.log(parser(html)); // Look #Result PostHTMLTree
+```
+
+#### input HTML
+```html
+<a class="animals" href="#">
+    <span class="animals__cat" style="background: url(cat.png)">Cat</span>
+</a>
+```
+
+#### Result PostHTMLTree
+```js
+[{
+    tag: 'a',
+    attrs: {
+        class: 'animals',
+        href: '#'
+    },
+    content: [
+        '\n    ',
+            {
+            tag: 'span',
+            attrs: {
+                class: 'animals__cat',
+                style: 'background: url(cat.png)'
+            },
+            content: ['Cat']
+        },
+        '\n'
+    ]
+}]
+```
+
 ## License
 
 [MIT](LICENSE)