Updates readme.txt details

git-svn-id: https://plugins.svn.wordpress.org/prismatic/trunk@2142183 b8457f37-d9ea-0310-8a92-e5e31aec5664

readme.txt

@@ -31,7 +31,7 @@ Display beautiful code snippets with Prism.js, Highlight.js, or plain code escap
 * __Highlight.js__ - Code escape + syntax highlight using [Highlight.js](https://highlightjs.org/)
 * __Plain Flavor__ - Code escape without syntax highlight
 
-Check out a [demo post using Highlight.js](https://dev-tricks.com/favorite-highlight-js-styles/)
+Check out a [demo post using Highlight.js](https://dev-tricks.com/favorite-highlight-js-styles/). I also use this plugin at [WP-Mix](https://wp-mix.com/) for all code snippets.
 
 
 **Prism.js Features**