[RFC]: Improvements to @stdlib/nlp-expand-contractions

### Description

We're writing as we found your library to be the most tested and fastest for expanding contractions. For context, we're working on https://spamscanner.net and expanding contractions before passing to tokenizers for spam classification.

To clarify, this is with regards to the generated codebase from the source at .

We noticed that your library is missing quite a few contractions in English, and could also benefit from contractions from other languages too (perhaps with an option).

While we can open a PR, we wanted to check to see what your thoughts were on this and how you might want the PR to look like (integration wise; e.g. new options?).

Here is our current compiled list of research and findings:

- List of contractions research
- https://en.wikipedia.org/wiki/Wikipedia:List_of_English_contractions
- https://en.wiktionary.org/wiki/Category:English_double_contractions
- https://gist.github.com/loretoparisi/c221a9c55fb71a23ff4e7bba3b794425?permalink_comment_id=4198425
- https://www.enchantedlearning.com/grammar/contractions/
- https://github.com/NaturalNode/natural/issues/533
- https://github.com/anton-bot/expand-contractions/pull/1
- https://github.com/kootenpv/contractions/blob/master/contractions/data/leftovers_dict.json
- https://github.com/kootenpv/contractions/blob/master/contractions/data/slang_dict.json
- https://github.com/stdlib-js/nlp-expand-contractions/blob/main/lib/contractions.json
- https://github.com/stdlib-js/nlp-expand-contractions/blob/main/lib/expand_contractions.js
- https://github.com/textlint-rule/textlint-rule-preset-google/blob/master/packages/textlint-rule-google-contractions/src/textlint-rule-google-contractions.js#L67-L87
- https://web.library.yale.edu/cataloging/months
- https://www.wikidata.org/w/index.php?search=%2B%22Category%3A%22+%2B%22contractions%22&title=Special:Search&profile=advanced&fulltext=1&ns0=1&ns120=1
- There are so many other lists that we can scrape:
- For example, French contractions: https://en.wiktionary.org/wiki/Category:French_contractions
- Here are other contractions we think should be included (that were not found elsewhere)
- 'twas -> it was
- 'tisn't -> it is not
- ma'am -> madam
- mightn't've -> might not have
- mustn't've -> must not have
- ne'er-do-well -> never do well
- o' -> of
- o'clock -> of the clock
- she'd've -> she would have
- shouldn't've -> should not have
- wouldn't've -> would not have

### Related Issues

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### Questions

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### Other

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### Checklist

- [X] I have read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [X] Searched for existing issues and pull requests.
- [X] The issue name begins with `RFC:`.