bug#51247: 28.0.60; Insufficient documentation of tab-bar.el internal functions

[Juri Linkov]

> Then the doc string after my changes is exactly right.  I have no idea
> what you see that's wrong with it.  You say some functions return menu
> items and some return a list of menu items, and that's what the doc
> string says.  You say that these values are displayed on the tab bar,
> and that's what the doc string says.  So what exactly is wrong??

  Adding a function to the list causes the tab bar to show
  that string, or display a menu with those menu items when
  you click on the tab bar.

It says that only when you click on the tab bar,
those menu items are used to display some menu.
But in fact those menu items are used to display
tabs or buttons, without clicking.
This is more correct:

  Adding a function to the list causes the tab bar to show that string,
  or display tabs or buttons created from those menu items.