A new era for Cloudflare Pages builds

> This is outstanding. Thank you!

> One request I would make for consideration is about the build images going forward: the ability to request that certain things be added. For example, Hugo users would find it extremely useful to specify not only `HUGO_VERSION` as is already possible but also `DART_SASS_EMBEDDED_VERSION` (or whatever you want to call such an env var), to enable use of Embedded Dart Sass with Hugo. Right now, there are workarounds for it but they're clunky and, I'd guess, subject to failure whenever you folks change things.

> But, again... great! Thanks!