Provide some guidance / a system for including additional front-end scripts

[equivalentideas]

Currently the one script included is the theme switcher, linked to individually in the base layout. Many users will want to include additional scripts for things like modals for example.

It would be handy to have some kind of compile going on, so additional scripts could be dropped into the scripts folder, or have their npm modules referenced somehow, and then include them all like the scss setup.

I'm not sure what the best approach here is :)