Black method parameters highlighting

[worldbeater]

Made some color tweaks, so now C# syntax highlighter uses black color for lambda parameters, function parameters, and private fields. Color keys are taken from scope-names.json that GitHub uses. More info on this can be found here.

Please, take a look at how it works now:

Not yet tested this in Atom.

[worldbeater]

Tested this in atom, so far looks nice.

@damieng need a review. Thanks in advance :)

[damieng]

This looks great!! Nice job :)