[WIP] Add command reference

[craddm]

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:vertical_traffic_light: Depends on

:arrow_heading_up: Summary

Adds a new top-level section to the documentation. This section shows the documentation for all of the available dsh commands using Typer rich console formatting.

:closed_umbrella: Related issues

:microscope: Tests

Documentation only

[github-actions[bot]]

Coverage report

This PR does not seem to contain any modification to coverable code.