Add a contributors section

[apmoore1]

How to format this section:

• It could be formatted so that each language has a list of contributors
• Should contributors have a label on what they contributed e.g. adding to the lexicon and/or editor of the lexicon like in the Turing Way project where these are emoji key.
• Overall contributors section for contributors that have perhaps been involved in all/most languages.

[apmoore1]

You can get a bot that can automatically add contributors: https://allcontributors.org/

The all contributors website also has a really good specification for contributors that can be applied to contributors that are not on GitHub.

I think this issue could be added to the PyMUSAS project, what do you think @perayson ?