A Couple Fixes, Tweaks and a Feature

A couple things in this pull request:

1. I fixed some whitespace inconsistencies throughout the file (for example, the use of tabs for alignment in the HiLink definitions when no other tabs exist in the file) and cleaned up some trailing whitespace.
2. Renamed the `Quote` matchgroup to `jsonQuote`, then `HiLink`'d that back to `Quote`. This provides colorscheme maintainers a finer level of granularity with their themes if they so prefer.
3. Added `jsonNoise` group that targets `:` and `,`, and mapped it back `Noise`