Add global-box-sizing for Susy

This is added to remove output from CSS file that adds box-sizing to
Susy Grids elements. Previously swore this didn't fix the issue, but it
is fine now, less duplicate CSS.  :)
Update WordPress Tags

I guess there are recommended tags I was unaware of, this is a guildline
for themes in the WP repo, which this theme is not, but I still want to
promote good practices to others, link
https://wordpress.org/themes/about/
Rebuild Styles

Addresses the WP guideline for Tags, there is a specific list of ones
that have to be used. Also set Susy to correctly use global-box-sizing,
which removes a bunch of duplicate styling.