Gleam Support

[lassejlv]

Support for the gleam language

[aleksrutins]

Just putting this out here in case someone else gets to this before me, in case it's helpful:

This'll be easier to implement here than in Nixpacks, since Mise can handle version constraints for us. I talked to the Gleam team while building Gleam support in Nixpacks (which never was fully functional because of this), and (from what I recall) going by the gleam_stdlib version for a compiler version is a valid strategy, but only the major and minor versions. The patch releases of the compiler have important security and compatibility fixes, and do not necessarily line up with the patch releases of the stdlib.

[iloveitaly]

@lassejlv @aleksrutins Definitely open to a PR here! This is a great example of what it takes to add language support to railpack.