Is your documentation request related to a problem? Please describe.

Currently, because tedge and similar binaries are not present when building the documentation, so constructs like:

    ```sh command="tedge config list ..."
    ```

can work when serving docs locally, i.e. the output of the command is put in the block, but when the docs is deployed, this binary is not present there, so the block is left empty.

Having the ability to run tedge command in docs would be very good for ensuring that outputs like help texts and config option listings are kept up to date and that we don't forget to update them after they change, which we have to do now by manually copying the output text generated locally into the blocks.

Describe the improvement you'd like

1. Have tedge and other thin-edge binaries in the environment where docs are built for production.
2. Add a local warning/error/CI check to always provide a fallback value when a shell command block is used in case the server can't generate it. I'd expect adding an empty check inside the sh component in remark/cmd-run/index.js would do it?