Update about.liquid to include background image

Author: sajeedmehrab

_layouts/about.liquid

@@ -1,7 +1,7 @@
 ---
 layout: default
 ---
-<div style="background-image: url('/assets/img/lab_logo.png'); background-size: 100% 100%; background-position: center; background-repeat: no-repeat; padding: 20px;">
+<div style="background-image: url('/assets/img/background.png'); background-size: 100% 100%; background-position: center; background-repeat: no-repeat; padding: 20px;">
 <div class="post">
   <header class="post-header">
     <h1 class="post-title">