[tlbuild] Pretesting TeX Live 2024

[Karl Berry]

    I suggest the section "Initializing from a current installation" 

Thanks Bob. I just added it a couple days ago. Because I can't give a
one-size-fits-all command sequence to do the big copy while preserving
symlinks, I was reluctant to make it too prominent, but I will ponder.

    I'm afraid "whatever your TL-current directory is" 

Ok, I'll try to reword. The idea is to copy the directory of the TL
installation that's getting updated nightly. I guess by default that
would be /usr/local/texlive/2023 (for the 2024 pretest), but OTOH some
people (or maybe it's just me) keep /2023 to be the initial release and
use a different directory for the "up-to-the-minute" install. Hmm.

Thanks for the feedback.  -k