(doc) Overhaul package moderation docs

[pauby]

This is a replacement for #624. Note that some of the comments on that PR have not been addressed and need to be.

Overhauling the package moderation docs to make them easier to follow for both moderators and maintainers going through the process.

Motivation and Context

Many reasons. #119 has the best explanation.

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

#119