Add shortcode for Google Map

[jimmyandrade]

As we can see at:
https://github.com/jimmyandrade/shortcake-bakery/blob/master/inc/shortcodes/class-google-map.php

Code uses build_map_link() and urlencode_address() to generate Google map urls.

[davisshaver]

@jimmyandrade This looks good/useful (and sorry for the Github deluge this morning).

We are currently working for the v0.1.0 release. If you'd like to get this in, we'd probably need a pull request with test coverage. We'll also help with code review and adding documentation. Otherwise we'll hold this issue in the backlog until we can work it into project planning.

[jimmyandrade]

@davisshaver No problem. I stayed a long time without being able to discuss about these issues. I'd like some help to create the tests, so maybe we could bring the Google Maps in the next release...