This reverts commit c9aa876b4cc679b19c736acc5951f6e640bcbbf2.

The planned `magit-section-jumper' class, for which this was added,
did not pan out.

Iff no docstring is explicitly specified for the command and the
class's `docstring' is set.

This likely still needs some refinement, so leave it undocumented for
now.  Meanwhile, see the `magit-section-jumper' class for an example.

This reverts commit 834869e0bfc5043b9f40598f724b9d40f9da87b8.

Turns out that wasn't added until Emacs 28.1.

When we created `transient--get-savable-value' in [1: b4edb633], we
(intentionally) stopped falling back to `transient-current-suffixes'.
The value is saved to history before `transient--suffixes' is unset
and our commands that explicitly set the value do not exit the menu.

However, a third-party may add a command that sets the value and
also exits the menu.  I realized that when I made the above change,
but figured I would hear about it, if anybody actually did that.
That just happened with #410, so use `transient-current-suffixes'
again.

Closes #410.

1: 2025-08-16 b4edb633488fc251df0883b69b1eb350cb2e94ec
   transient-get-value: Replace with three functions

Correct IMO, obviously.