Docs: Link to the browser support page in CONTRIBUTING.md

Instead of duplicating the supported browsers matrix, just link to
the browser support page on jquery.com.

(cherry-picked from 5801c3a2)

CONTRIBUTING.md

@@ -207,10 +207,8 @@ This will only run the "css" module tests. This will significantly speed up your
 **ALWAYS RUN THE FULL SUITE BEFORE COMMITTING AND PUSHING A PATCH!**
 
 
-### jQuery supports the following browsers:
+### Browser support
 
-* Chrome Current-1
-* Safari Current-1
-* Firefox Current-1
-* IE 6+
-* Opera Current-1
+Remember that jQuery supports multiple browsers and their versions; any contributed code must work in all of them. You can refer to the [browser support page](http://jquery.com/browser-support/) for the current list of supported browsers.
+
+Note that browser support differs depending on whether you are targeting the `master` or `1.x-master` branch.