Update README for nmp-arm

[LocalNewsTV]

Describe the task
Update the README.md's for nmp-arm.

Purpose
Documentation is not up to date in many of the READMEs. As new developers are brought into sustainment team, this is often the first place they're looking for how to setup their environments.
Lack of documentation can lead to confusion and inconsistencies.

Acceptance Criteria

• Update all READMEs for nmp-arm
• Add detailed developer setup instructions

Additional context

• READMEs are public facing and careful consideration should be planned to not include any secrets or private information (e.g. Passwords)