Added logo mark

Author: fieg

README.md

@@ -1,7 +1,13 @@
-Infinite Ajax Scroll
-====================
+<p align="center">
+<a href="https://infiniteajaxscroll.com" target="_blank">
+<img alt="Infinite Ajax Scroll" title="Infinite Ajax Scroll" src="https://infiniteajaxscroll.com/img/infinite-ajax-scroll-mark.svg" width="180">
+</a>
+</p>
+<h1 align="center">Infinite Ajax Scroll</h1>
 
-Turn your existing pagination into infinite scrolling pages with ease. Key features include:
+Turn your existing pagination into infinite scrolling pages with ease. 
+
+Key features include:
 
 * SEO friendly 🥇
 * Doesn't break browsers back button 💯