Add getter for the Modifiers struct to Keyboard

[iTitus]

Closes #39

[thejpster]

Please run cargo fmt and squash the change into the last commit. Thank you!

[iTitus]

Squash the change into the last commit. Thank you!

You can squash merge with GitHub: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/incorporating-changes-from-a-pull-request/about-pull-request-merges#squash-and-merge-your-commits

[thejpster]

Yes, I am aware how Github works.

My default position is that any proposed set of git commits should form a reasonable and understandable set of changes. Formatting should be squashed into whichever commit changed the line that broke the formatting check. In this case, there is only one change and I am happy to squash it for you.