Enhancement: Update md output mode to exclude nested properties in `md` output mode.

[martinlingstuyl]

Related to #4150 where we determined that the csv output mode should show all properties, except nested objects. Nested objects should only be visible when expressly selected using the --query option.

This issue is solved when the same is applied to md:

• exclude nested options by default.
• include nested options only when --query is used.

[waldekmastykarz]

Let's clarify the spec: nested properties should be available for querying, but in the end will still be removed, because we can't render them in a meaningful way in md.

[martinlingstuyl]

That's the same for csv though. I'd say: keep it the same, if people want to show them they can. Who knows what they'll do with the output. Maybe they'll do some further processing.

[waldekmastykarz]

Correct. I only mentioned md here, because this issue refers specifically to md format, but indeed, md and csv would be the same.

I'd say: keep it the same, if people want to show them they can

I don't think there's anything you could achieve with such output, so I'd say let's take it out. If we find a better way to go about it, we can always add it.

[nicodecleyre]

I would like to give this a go

[milanholemans]

Nice to hear @nicodecleyre, it's all yours!