Add `indent-guides` and `whitespace.render` to be language dependent

[Teknomancer]

Whitespace render
While working with certain files (eg. Makefiles) where tabs vs spaces are significant, it's desirable to always render tabs and spaces. While working with certain other files it's not.

Indent-guides
While viewing/working with diff files, the indent-guide settings are off because I have the following in the main config.toml:

[editor.indent-guides]
render = true
character = "┊"
skip-levels = 1

When opening diff files, the indent guides are rendered "wrong" because the diff +/- changes the normal indent level of the C/CPP file. Example screenshot:

It would be convenient if these two settings indent-guides and whitespace.render are allowed to be specified in languages.toml so they can be set depending on the language of the file being worked on.