TASK: Documentation tweaks, add CR command reference

[kdambekalns]

• This does some cleanup and improvements to the documentation.
• Tweaks documentation-related settings.
• Slightly cleans up some code (CR commands)

Checklist

• Code follows the PSR-2 coding style
• Tests have been created, run and adjusted as needed
• The PR is created against the lowest maintained branch
• Reviewer - PR Title is brief but complete and starts with FEATURE|TASK|BUGFIX
• Reviewer - The first section explains the change briefly for change-logs
• Reviewer - Breaking Changes are marked with !!! and have upgrade-instructions

[bwaidelich]

This is fantastic, thank you.
I only skimmed over the changes and could not find any obvious error, so +1 by reading.

We should merge this asap to prevent conflicts