Support things like Brewfile

[ansidev]

Is your feature request related to a problem? Please describe

I am migrating to a new device.
I have to install plugins and packages manually.

Describe the proposed solution

I want a solution to like Brewfile of Homebrew.
I can write a file that defines all plugins and package versions. Then asdf can read it and install things automatically.

Describe similar asdf features and why they are not sufficient

N/A

Describe other workarounds you've considered

Use plugin-add and install and do things manually.

[hyperupcall]

Thanks for filing the issue

Looks like a duplicate of #1616, #1564, #1577, #829, #240
And similar to #1678