use-package has been merged into emacs-29

[Stefan Kangas <stefankangas@gmail.com>]

Hi Emacs,

Just to make this official: use-package has now landed on the emacs-29
branch.  This means, barring any major world disasters, solar storms, or
similar, use-package will officially be a part of Emacs 29.

I completed the final steps of the merge and rewrote the user manual.
However, the main credit naturally belongs to use-package's principal
author John Wiegley.

It's also worth highlighting the numerous contributors from the user
community writing patches, bug reports and documentation over the years.
These are the top 15 contributors (number of commits on the left):

    $ git shortlog -a -s -n | head -15
       615  John Wiegley
        37  Noam Postavsky
        34  Jonas Bernoulli
        26  Radon Rosborough
        22  Stefan Kangas
        17  Justin Talbott
        15  Phillip Lord
        11  Adam Spiers
        11  Damien Cassou
        11  Kaushal Modi
        10  Alex Branham
        10  Jimmy Yuen Ho Wong
         9  Ted Zlatanov
         8  Nicolas Richard
         8  Payas Relekar

Thanks also to Payas Relekar, without whose insistent posts to
emacs-devel, this merge would have never happened in time for Emacs 29.
Together with João Távora he also provided the substantial portion of
the merge scripts, which saved me a lot of typing.

Thanks all, and congratulations Emacs!