update readme

Author: lindelof

README.md

@@ -1,3 +1,7 @@
+<p align="center">
+  <img src="https://github.com/lindelof/particles-bg-vue/blob/master/images/logo.png?raw=true"/>
+</p>
+
 # particles-bg-vue
 
 [![NPM](https://img.shields.io/npm/v/particles-bg.svg)](https://www.npmjs.com/package/particles-bg) [![JavaScript Style Guide](https://img.shields.io/badge/code_style-standard-brightgreen.svg)](https://standardjs.com)