Save or cache theme files locally

[haveanicedavid]

Sanity checks

• [X] I have searched github.com/withfig/fig/issues and there are no duplicates of my feature

Feature Details

Description:

Fig’s theme switching works great while there's internet access, however changing themes without seems to stall. It would be great to cache or save the theme files locally, so I can toggle between them even if I don’t have access (on a plane, for example)