Link to codepen collection

Added a link to a codepen collection with other hexagon patterns

Author: web-tiki

README.md

@@ -53,3 +53,10 @@ s = horizontal spacing between hexagons
 
 m = - h + h * cos(60deg) + s * sin (60deg)
 ```
+## Other patterns for the hexagon grid
+For other patterns:
+* different number of hexagons per row
+* other centering options
+* have less hexagons on the even rows than on the odd ones
+ 
+you can check this [codepen collection](http://codepen.io/collection/npgxpm/)