md syntax fix

Author: tevko

readme.md

@@ -122,7 +122,7 @@ The only external dependency included in this plugin is Picturefill - v2.3.0. If
 - Check if wp.media exists before running JS
 - Account for rounding variance when matching ascpect ratios
 
-** 2.1.1 **
+**2.1.1**
 
 - Adding in wp-tevko-responsive-images.js after file not found to be in wordpress repository
 - Adjusts the aspect ratio check in tevkori_get_srcset_array() to account for rounding variance