Front-end styling for the new Directory Facets checkbox template

[Adnan-cds]

We have just merged support for the facets_form module into the localgov_directories module. This has brought in a new Twig template into the localgov_directories module which now needs some Front-end love. Following Andy's suggestion, I am raising this request here instead of the localgov_directories module. I hope that's okay.

FOA @cjstevens78 @markconroy