Add support to flatten nested keys fixes Better handling of nested keys

[evilhamsterman]

Fixes #26

[evilhamsterman]

This adds the support I mentioned. It also runs the keys through normalize_keys as it does, so if you have concerns about odd characters in keys it can be added there.

[josheppinette]

@evilhamsterman thank you for the pull request, I will get it reviewed ASAP

[josheppinette]

@evilhamsterman I am going to re-PR this after making some edits to pass the pre-commit checks, but will make sure you are marked as author

[evilhamsterman]

My code is your code

[josheppinette]

Closing in favor of #33.

CC: @evilhamsterman