Consider renaming --parent to --parents

[jrz]

Is your feature request related to a problem? Please describe

Just upgraded to 0.16.
I noticed the --parent option with asdf set.

Now, the documentation/help text is actually clear, but from just the option, I thought it would set in the tool-version of the direct parent (which doesn't really make sense)

Describe the proposed solution

Change --parent in --parents

Describe similar asdf features and why they are not sufficient

asdf --parent

Describe other workarounds you've considered

not applicable

[Stratus3D]

I've got no objection to this. PR welcome!

[jrz]

@Stratus3D thx. Should I create a (temporary) fallback or just error when someone (still) uses --parent?

[Stratus3D]

@jrz a fallback if it's not too complicated, I haven't investigated.