as a nix user it would be nice if roc supported hashing for non-remote-url destinations.

specifically,

• a local tar file
• a local directory with a main file

one idea:

• right now the module location is either URL or localFilePath
• continue allowing localfilepath but going forward
• enable 'file' schema and implement ?hash
  • allow tar, tar.br, tar.gz files
  • allow ./localDir/main.roc to be used (perform appropriate bundling to obtain hash if needed)

references:

• file schema:
  • https://www.rfc-editor.org/rfc/rfc1738.html#section-3
  • https://www.rfc-editor.org/rfc/rfc8089.html#appendix-B
  • https://en.wikipedia.org/wiki/File_URI_scheme
• roc2nix:
  • https://github.com/JRMurr/roc2nix#todo
  • blake3 hashing JRMurr/roc2nix#2
  • Add BLAKE3 hashing algorithm NixOS/nix#12379 (comment)