First 15 - Manual; Admin and Linux

[DaintyJet]

Overview of Changes

Markdown and expanded version of First 15. most of this is covered by the Ansible Scripts but gives a good overview of things.

Reason for Modification

Having formalized First-15 min documentation is good fo future reference.

Verification

• [x] The documentation is completed, or does not contain work-in-progress/partially-completed sections.
• [x] The documentation is written in Markdown (Exception for Inject and Incident Reports).
• [x] Any Images are contained in a subdirectory Images.
• [x] Any scripts, Ansible Playbooks, Terraform scripts, etc. Have documentation explaining their purpose and use case.
• [x] Any scripts are tested.
• [x] I have assigned and notified a reviewer.