feat(descriptions): expand information for key and code

[cwadrupldijjit]

What Changed?

• add more explanations about behavior of .key and .code event properties
• remove extraneous parentheses surrounding deprecated
• add cross-env to allow for Windows users to run the app with the node options supplied in the env

Issues Addressed:

• N/A

Issue Testing:

• Manual Developer Testing

Test Results:

1. Open browser to running application
2. Read the descriptions on the page for the .key and .code values
3. See that they add clarity to the behavior of their respective properties