build: add lint instruction to makefile to alphabetize and normalize words

[nathanhleung]

By alphabetizing the word list and normalizing each word by turning it to lowercase, we make it easier for contributors to add words to the library without worrying about duplicating entries.

If a contributor adds a new word and then runs make lint, they'll be able to clearly see in the diff if they added a duplicate since it will be right before or after the already existing word.

[nathanhleung]

@web-mech Thanks for this library; it's been exciting to see the recent new releases. Would love to hear your thoughts on this PR.

[web-mech]

LGTM. We'll integrate a CI/CD pipeline in the near future and make this a part of it