To add a phone number in your custom content, just add a link with the href set to `tel:1234567890`, where the number is replaced by your phone number.
The following will produce a phone number link to the number 555-555-5555 with a mobile phone icon next to it.
<a href="tel:5555555555" class="shiftnav-tagline"><i class="fa fa-mobile"></i> 1-555-555-5555</a>
When clicked or tapped on a device with phone capabilities, the link will prompt the user to initiate a call.