🥳 Resolve Vercel serverless functions overuse problem

This is a big deal because Vercel asked me to upgrade to an Enterprise plan because of this 😲 Now everything is completely static, and I moved every dynamic part (rss & atom feeds) directly to the backend. They use the same URL (so customers wouldn't notice any change). Will send Vercel tomorrow once all pages are redeployed that I don't use functions no more :P