feat: introduction of devshell

[aldoborrero]

This PR introduces devshell rather than using mission-control

[selfuryon]

LGTM, but just curious, why not devenv or similar projects?

[aldoborrero]

@selfuryon I chose devshell as it's quite similar to mission-control but removes extra mambo jambo that regular mkShell introduces into the system variables when loading the dev environment.

And why not devenv? Mostly it's a personal preference, I do believe it introduces too much that, probably, we won't need in the near term. We don't need features like processes, languages, containers, etc. Even if we do someday, I prefer to incorporate more fine-grained tools like process-compose or another similar tooling. I prefer to favor the Unix philosophy (do one thing very well).

Also with devshell I can optimize the repository much faster if necessary as I'm working with Numtide (the owner of the repository) these days.

As with everything, it's not set in stone, so we can evaluate at a later date another tool that suits us better (even devenv, I'm not excluding it by any means). I'm always open to exploring new ideas.

[brianmcgee]

@aldoborrero can you sign the commits?

[aldoborrero]

Mmm, it seems hercules-ci is behaving weirdly today...

querying info about missing paths
querying info about '/nix/store/22z4n4mxs2vz3l3lg41dz3mgnq1d4wxs-source' on 'https://cache.nixos.org'
downloading 'https://cache.nixos.org/22z4n4mxs2vz3l3lg41dz3mgnq1d4wxs.narinfo'
copying path '/nix/store/22z4n4mxs2vz3l3lg41dz3mgnq1d4wxs-source' from 'https://cache.nixos.org'
downloading 'https://cache.nixos.org/nar/1hq8i3v4jik16jpn3gh0c11rbkq85x040m8f5fml43swgd4w1qgd.nar.xz'
warning: error: SQLite database '/nix/var/nix/db/db.sqlite' is busy

[selfuryon]

LGTM