refactor: clean up checks

[Nytelife26]

It has come to my attention that a lot of checks within proselint are dubious at best, or misguided. For instance:

• "Christiana" being considered archaic - it is the name of a place. and of a riot, too.
• The filter that quite literally just checks for text matching "the n-word" - what use is telling people not to use a way to refer to it, if we aren't telling people the harm done by the word itself?
• The hundreds of phrases and words in the cursing.nfl check - some of them are just numbers, and others have many variations included, almost like a poorly-designed censoring system, in contrast with using regex.
• The categorization of various corporate types as different - why have airlinese, corporate speak, etc in different categories? They should logically be in different subcategories under corporate jargon.
• The same for LGBTQ and sexism - why not put both, and more, under a discriminative / exclusive language based module?

Et cetera. I feel it may be necessary to do a refactor of these checks and categorizations with a formal review to make maintainability easier in future and also to maintain a better linguistic ecosystem.