Add config option to save generated rules and styles directly to the source files

[anxpara]

🆒 Your use case

I'm using Sveltekit and Vercel

🆕 The solution you'd like

I'm not a particular fan of magic code being injected after I deploy my site. I'd much prefer to have Fontaine save anything it generates to my repo so I can look everything over and commit it to my repo.

🔍 Alternatives you've considered

No response

ℹ️ Additional info

No response

[anxpara]

I don't want to add the fontaine package to my repo because of this issue: #562 (comment)

So until that is fixed it would be especially nice to have fontaine just save the generated rules once so I can uninstall it. Instead I'll have to hunt through dev tools to find the generated rules and save them manually.