support for multiliungal tokenizer with hooks for malayalam, adding range support

[dsplog]

fix for #29 and support for malaylam

    text = 'hello (1200 - 1230)'
    out = normalize_text(text)
    print(out)
    hello (one thousand two hundred to one thousand two hundred thirty)

[yl4579]

I would recommend you create a new branch for this so I can merged and refer to people to this branch in README. I don't want to mess up with the current branch.

[dsplog]

I would recommend you create a new branch for this so I can merged and refer to people to this branch in README. I don't want to mess up with the current branch.

can you plz create a new branch, and will change the merge destination on PR.

[yl4579]

Yes I did: https://github.com/yl4579/PL-BERT/tree/multilingual