Adding Phone To helper like mail_to for handling phone numbers

Adding Phone To helper like mail_to for handling phone numbers

Useful for mobile browsers and desktop browser with phone supported software.

Creates a tel link tag to the specified +phone_number+

Accepts blocks

Ah, I see. I think we should flip the order of the arguments to match that of `link_to`, which also means that we should be able to call `link_to` from within this method.