Fonts, specifically courier prime sans

[JadeNeoma]

It would be great if we could use other fonts, courier prime sans is personally my favourite flavour because serifs look awful imo. In the absence of actually adding fonts looking at reworking the fonts system to make it feasible to add our own fonts would be great. I added sans to the fonts package myself bcs its super easy (I have decided not to create a pull request to their repo bcs I don't have the time to do it properly) so using a similar system to theirs would be ideal.