hmm, it's not in the `--help` or man page. looks like an alias of
subcommand `show`.

ref:

[https://salsa.debian.org/apt-team/apt/-/blob/main/cmdline/apt.cc]

On Sat, Jul 29, 2023 at 3:08 AM Aaron Schrab <aaron@schrab.com> wrote:

> At 13:15 +0800 28 Jul 2023, Terrance Hendrik <terrance.hendrik@gmail.com>
> wrote:
> >Please add `apt info` as same function as `apt install` into
> >`_apt-cmd` of
> >`functions/Completion/Debian/_apt`
>
> That doesn't appear to be documented as an apt subcommand, I don't see
> it in either the apt(8) manpage or the output of `apt help`.
>
> However both of those sources *do* mention `apt show` which seems to do
> the same. That *is* supported by the completion code, and would probably
> be a better thing to clone if support for `apt info` were to be added
> (although since `install` and `show` just seem to complete all packages
> I don't think it matters much currently).
>