Suggestion: add note about httpredir to debian.org/mirror/list

Hey,

friends of mine were unaware that http://httpredir.debian.org/ exists and
pointed out that our official documentation doesn’t mention it.

Specifically, they read https://www.debian.org/mirror/list and then
proceeded to hand-pick a mirror.

I think it would be beneficial to our users if we added a note like the
following at the top of the page:

"""
Use http://httpredir.debian.org/ to automatically get the best mirror based
on your geographic and network location. In case httpredir does not work
for you, please send a report to [email protected] and select a mirror
from the following list for the time being:
"""

What do you think?

P.S.: Please CC me as I’m not subscribed to this list.

-- 
Best regards,
Michael