Remove deprecated root-level options

[ark120202]

This removes the need to add lua before option names and would look better if more options would be added.

{
	"lua": { // or tstl
	 	"target": "5.3",
	    "libImport": "inline"
	}
}

Another module that extends tsconfig, awesome-typescript-loader, is doing the same.

[Perryvw]

Looks like an interesting idea, but why not create a luaconfig.json instead then?

[lolleko]

I don't think it matters much if its in its own object or just in the config root. Might be slightly nicer to have them grouped. But such a change would break all existing projects, which kinda sucks.

Im absolutely against having another config file, that will just make things more messy and harder to maintain imo.

[ark120202]

But such a change would break all existing projects

Can't it be the same as with old compiler directives? Deprecate old names, use them as a fallback and remove in 1.0.0 (#365).

Im absolutely against having another config file

+1 on this, most projects already have quite a number of config files.

[Perryvw]

I think indeed a path forward would be to support both for a while and eventually get rid of the global settings. I also agree another setting file might just end up cluttering the root of the project (look at the stuff in this project alone).

[ark120202]

Supported since #463 and root-level options were deprecated in #511.