Include Settings in the ProjectLayout

[arendjr]

#4846 introduced the ProjectLayout, but it only includes for NodeJsPackage for now. I want to include Settings there as well, so that we can store settings from nested biome.json files too.

One other thing we'll need to do is to let nested biome.json that don't specify an extends field, to extend from parent configs transparently. If desired, we can also split that into a separate issue/PR.

[ematipico]

to extend from parent configs transparently

What's the rationale? Are there specific requirements or will it be the default behaviour for all biome projects?

[arendjr]

I think it should be the default behaviour indeed. I think it aligns most with user expectations.

[arendjr]

One thing I forgot about is this comment has a useful suggestion for an "extends": "//" syntax that can be used to extend the root config. That’s probably even better than the implicit suggestion I made above.