Import-able configs

[srid]

Allow sharing mission-control configs among multiple projects.

For example, many Haskell project reuse these scripts. It should be possible to import them one-line rather them duplicating them in every project.

cf. https://matrix.to/#/!gcrYWdPsIUOFpXFDHB:matrix.org/$j3lN4rCpqlbKtHH_pEtGE3n-1iRUGQ1hHlU8RzHCvvU?via=matrix.org&via=nixos.dev&via=gaze.systems