Feature Request: per language settings for default tab size

[wulftone]

The tabSize defaults to the editor default value when making a new file, and there are different standards in different languages. It would be super helpful to have a per-language default tab size option available. I've encountered that even after adding some content with the correct number of spaces per indent, saving the new file, then re-opening it, it still doesn't correctly detect the right tabSize all the time. A per-language default would make this a much simpler operation.

[rmunn]

The EditorConfig plugin can help with that if you create an .editorconfig file at the root of each repo, but a per-language default setting would be easier.

[bpasero]

/cc @sandy081

[sandy081]

Duplicates #1587