[feat] create an online `nix-locate` service

[loynoir]

[Ryan Lahfa]

search.nixos.org ?

[loynoir]

@RaitoBezarius

• search.nixos.org seems not support search package using file.

• https://pkgs.alpinelinux.org/contents

[Ryan Lahfa]

Then, shouldn't this be a feature request with search.nixos.org to add a /contents URL and use the locate database inside the browser?

[Sandro]

dupe of #194