Created by: MartijnCuppens
Negative margins were introduced to create/hack responsive gutter widths in BS 4.2. But since we now have the responsive gutter, those classes are now less applicable. Also, since we now have an xxl
breakpoint, our file size has increased quite a lot, since there are lots of negative margins.
Negative margins can be useful, but I don't think we should enable them by default, therefore using a $enable-
variable feels like a good idea.