Set engines in package.json

[einsteinsfool]

It would be nice to know which NodeJS versions are supported by fdir.
All that needs to be done is to add the code below to package.json:

  "engines": {
    "node": ">= 16.0.0"
  }

I deduced version 16 based on testing NodeJS on CI here.

[jakebailey]

Testing of 14 was removed in 3c608bd, but I don't think that actually introduced any new stuff; if the package really does support 14, it would be nice to declare that; mocha's engines are 14+ (as are TSs) so that would be sort of nice to have to replace glob or something.

Understandable if not.

[SuperchupuDev]

i believe that the library intentionally doesn't use newer node features to maintain compatibility, if the engines field is added it should reflect on what versions it works in even if testing on <14 was dropped

[thecodrr]

If engines is set to v14 then CI must also add tests for node v14 to make sure things remain working and there are no breaking changes.

Update: the tests don't run on node@14. If anyone can make them work on node@14 that'd be good enough to add node 14 to engines.

[SuperchupuDev]

adding an engines field to anything above >=12.0.0 would be a breaking change for tinyglobby users btw, would it be possible to keep engines compatibility with node 12 at least during this major version?

[jakebailey]

The version of vitest depended on in this repo only supports >=14.18, though I can't even seem to use that as something in the deps uses ||= somewhere.

The tests don't actually use any fancy features of vitest, so something simpler may be usable too, but I don't think this will be super simple. Not even vitest 0.1.0 supported Node 12.