Refine repo layout to prepare for downstream changes.

[harrisonCassar]

Currently, our repo's directory is quite minimal in its organization. Although it's simple, it does not in a very intuitive manner express through its organization what is deployed where (across Avionics and Ground Systems). In order to support future work/changes/additions, let's perform an overhaul now before things get more complex.

Blocks #16.

Requirements

The new directory layout should:

• Be robust to future changes, primarily the two larger TODOs downstream: future deployment infrastructure work (#16) and config-file work (not yet ticketed). Ideally, our directory layout should roughly match what we expect to see on the actual RPi/microcontrollers).
• Support the later integration of a nice-to-use test infrastructure (for CI).
• Support the addition of scripts that are NOT official FSW/GSW, but still relevant to supporting operations and/or development (i.e. dashboards (#24), auto-coding, calibration scripts (#11), etc.)
• Mimic what is typically done in industry.

[harrisonCassar]

Initial thoughts:

KEY:

• Red: not yet existing in our source code
• Blue: not version controlled (only possibly living on a local repo instance)
• Black: file/directory