Integrate App Pat Owner and App Dev docs into walk-through

[TechnicallyWilliams]

Description

As a user, I'd like to complete the guidance in the walk-through documentation without feeling like there are missing documentation steps scattered throughout various places in the Cobalt codebase.

Acceptance Criteria

Reference: [Done-Done Checklist] (https://github.com/Microsoft/code-with-engineering-playbook/blob/master/Engineering/BestPractices/DoneDone.md)

• Should be a part of the steps within the epic write-up of issue [EPIC] Documentation Rework #346

Resources

Technical Design Document
Mockups

Tasks

Stories are intended to be completed in a single sprint; if task breakdown creates addition work then team should discuss promoting the Story to an Epic.
Reference: [Minimal Valuable Slices] (https://github.com/Microsoft/code-with-engineering-playbook/blob/master/Engineering/BestPractices/MinimalSlices.md)

Reference: [How to Write Better Tasks] (http://agilebutpragmatic.blogspot.com/2012/04/splitting-story-into-tasks-how-to-write.html)

Assignee should break down work into tasks here