[tldistro] tl21 released

[Karl Berry]

Hello fellow TeX distributors - I've moved the tl21 and mactex21 images
and other files to the public areas on tug.org, and updated the web
pages (https://tug.org/texlive).

You can get the tarballs from the TeX historic archive
(https://tug.org/historic) in /systems/texlive/2021 if you want, or the
other usual places for the other usual files.

Let us know (mailing list please, I'll be offline for a few days)
if/when you find problems.

Happy TeX distributing. --karl