Add a Buy me a coffee button

README.md

@@ -78,7 +78,7 @@ If your project is not accessible from outside, or if you want to fork and impro
 ## Author
 Gaël Métais. I'm a webperf freelance. Follow me on Twitter [@gaelmetais](https://twitter.com/gaelmetais), I tweet about Web Performances, Front-end and new versions of YellowLabTools!
 
-<a href='https://ko-fi.com/supportkofi' target='_blank'><img height='35' style='border:0px;height:46px;' src='https://az743702.vo.msecnd.net/cdn/kofi3.png?v=0' border='0' alt='Buy me a coffee' />
+<a href='https://ko-fi.com/supportkofi' target='_blank'><img height='35' style='border:0px;height:46px;' src='https://az743702.vo.msecnd.net/cdn/kofi3.png?v=0' border='0' alt='Buy me a coffee' /><a>
 
 I can also help your company about Web Performances, visit [my website](https://www.gaelmetais.com).