feat: implement config package

[PierreDemailly]

TODOs

• Generics
• More tests
• Do we need async methods ? The package is full sync

I would appreciate a first review @fraxken

[fraxken]

I would have re-implemented it with async and the old test suite (not perfect but it was doing the job). Synchronous API are not idiot but require a deeper refactor.

And yes Generics is welcome

[PierreDemailly]

I've added some test and the coverage is now 97%

@fraxken WDYM by deeper refactor ? I'd like to implement both sync and async methods (read, readSync, writeOnDisk, writeOnDiskSync etc), do you think its better to skip sync and keep only async ?

[fraxken]

@PierreDemailly Some API has been designed to be lazy with async. Also having both make things a lot more complicated for me in term of how things are abstract.

[fraxken]

I would rename Config -> ConfigSync and save it into a separate files. And keep index to export.

[fraxken]

@allcontributors please add @PierreDemailly for code, docs, maintenance

[allcontributors]

@fraxken

I've put up a pull request to add @PierreDemailly! 🎉