Add emphasis to CONTRIBUTING

Author: xoofx

CONTRIBUTING.md

@@ -4,6 +4,6 @@ This project is an attempt to keep alive the original AjaxMin project developed
 
 I (xoofx) highly invite people to help to fix issues they find in this project, as I can't afford myself to be the sole maintainer of this project.
 
-In other words, Pull Requests (PR) are much welcome and most likely the only way for you to get your issue fixed and to help to keep this project alive.
+In other words, **Pull Requests (PR) are much welcome** and most likely the only way for you to get your issue fixed and to help to keep this project alive.
 
 Thank you!