Add cli wrapper

[kylefeng28]

Hello, I'm trying to learn Taigi right now, and I found your Taibun transliterator website pretty useful, especially the TTS feature which lets me hear the words and especially tone sandhi in context. Awesome work by the way!

I found that there was also a Python library, so I added a simple CLI wrapper which could be useful for quick usage in the shell (there's a text segmentation / morphological analyzer for Japanese called MeCab which is primarily CLI driven)

usage: taibun [-h] {convert,tokenise} ...

Taiwanese Hokkien transliterator and tokeniser

taibun convert:
  -s, --system {Tailo,POJ,Zhuyin,TLPA,Pingyim,Tongiong,IPA}
                        transliteration system (default: Tailo)
  -d, --dialect {south,north,singapore}
                        dialect variant (default: south)
  -f, --format {mark,number,strip}
                        tone representation (default: mark)

taibun tokenise:
  --no-keep-original  normalise tokens to traditional characters instead of preserving original input

Examples:

$ taibun convert '我今仔日想欲去買菜' # (default: -s Tailo -d south)
Guá kin-á-ji̍t siūnn-beh khì bé tshài

$ taibun convert '我今仔日想欲去買菜' -s POJ
Góa kin-á-ji̍t siūⁿ-beh khì bé chhài

$ taibun convert '我今仔日想欲去買菜' -s Zhuyin
ㆣㄨㄚˋ ㄍㄧㄣ ㄚˋ ㆢㄧㆵ˙ ㄒㄧㆫ˫ ㆠㆤㆷ ㄎㄧ˪ ㆠㆤˋ ㄘㄞ˪

$ taibun convert '我今仔日想欲去買菜' -s TLPA -d north
Gua2 kin1 a2 lit8 siunn7 bueh4 khi3 bue2 chai3

[andreihar]

Thank you very much for your contribution! Sorry for the long delay in approving the PR. I'll release a new version on PyPI soon.