Several missing token filter types

[JoshMock]

An issue was opened on the JS client repo noting the missing cjk_bigram token filter type. I went through the docs and identified several missing token filter types:

• apostrophe
• arabic_normalization
• cjk_bigram
• cjk_width
• classic
• decimal_digit
• flatten_graph
• german_normalization
• hindi_normalization
• indic_normalization
• keyword_repeat
• min_hash
• persian_normalization
• phonetic
• scandinavian_folding
• scandinavian_normalization
• serbian_normalization
• sorani_normalization

Assigning to myself, as I'd like to at least solve for the one reported on my repo, but it's a good opportunity to scan through the spec and knock out several fixes at once.