Add buttons copyright

afshinm · afshinm · commit c0fcc9b71a7b · 2013-03-20T01:07:36.000+03:30
diff --git a/introjs.css b/introjs.css
@@ -114,6 +114,10 @@
   text-align: right;
 }
 
+/* 
+ Buttons style by http://nicolasgallagher.com/lab/css3-github-buttons/ 
+ Changed by Afshin Mehrabani
+*/
 .introjs-button {
   position: relative;
   overflow: visible;
