Adds keystrokes to the Tools menu for (B)oards and (P)orts, as well is to those submenus themselves.

This is not only useful for switching more-quickly between projects, but also likely for accessibility, screen-readers, etc.

A couple functions have been added for selecting incremental letters/digits. They can be used for other menus as well.

All Submissions:

• [*] Have you followed the guidelines in our Contributing document?
• [*] Have you checked to ensure there aren't other openPull Requests for the same update/change?

New Feature Submissions:

1. [*] Does your submission pass tests?
2. [*] Have you lint your code locally prior to submission?

Changes to Core Features:

• [*] Have you added an explanation of what your changes do and why you'd like us to include them?
• [n/a?] Have you written new tests for your core changes, as applicable?
• [*] Have you successfully ran tests with your changes