Don't suggest only add_theme_support('custom-background') -- suggest it with...

Don't suggest only add_theme_support('custom-background') -- suggest it with $args even if it wasn't called with any arguments. In particular, default-color should be used by themes as a good user experience improvement. see #20249.



git-svn-id: https://core.svn.wordpress.org/trunk@20220 1a063a9b-81f0-0310-95a4-ce76da25c4cd