Clarify packaging documentation

[pauby]

Description Of Changes

Merging and updating the packaging documentation.

Motivation and Context

The documentation for packaging is in multiple places that should all be brought together.

Testing

• I have previewed these changes using the Docker Container or another method before submitting this pull request.

Change Types Made

• Minor documentation fix (typos etc.).
• Major documentation change (refactoring, reformatting or adding documentation to existing page).
• New documentation page added.
• The change I have made should have a video added, and I have raised an issue for this.
  • Issue #

Change Checklist

• Requires a change to menu structure (top or left-hand side)
• Menu structure has been updated

Related Issue

N/A

[pauby]

I have put this into draft just now. There are some major changes to our documentation in this PR now, or when I update it.

[pauby]

As a reminder, the GenerateDocs.ps1 needs to be updated with changes to the functions and cmdlets PowerShell reference pages.