bug#32990: 26.1.50; isearch-forward + t-m-m/mark-active doc

[Juri Linkov]

>> That does exit Isearch, but that doesn't seem to
>> be what the bug report was about - it says that
>> you cannot move the divider.
>
> Right.  It would be nice to be able to resize windows during Isearch
> without causing the latter to exit.  That would, however, amount to a
> feature request and the bug report did not ask for it.

This is now implemented in master for Emacs 27.