Add shortcodes for mailing address & phone/fax

[jimmyandrade]

• https://github.com/jimmyandrade/shortcake-bakery/blob/master/inc/shortcodes/class-mailing-address.php
• https://github.com/jimmyandrade/shortcake-bakery/blob/master/inc/shortcodes/class-phone.php

User could have more convenience when adding mailing addresses, which have come with schema.org notation. Phone/fax numbers could be linked if wp_is_mobile().

[davisshaver]

👍 to these. PR/test coverage will be next step, or we can come back after v0.1.0.

[jimmyandrade]

Great! If you need some additional info, just let me know :)