I don't really need it on this domain. Just move it to a different
location on a different domain instead

Rather than .../cgit/

This allows for a general redirect that can be used in multiple places
in the website in future, without it getting confused over the
/style/cgit/ directory.

Put redirects in to make old links/bookmarks still work. Not as if
anyone has made bookmarks already, but it's a good habit to get into.

It has all the benefits previously mentioned in commit 2f547251, as well
as mirroring the common programming convention of using a "_" prefix to
identify private variables/functions

Hides files beginning with _ from mod_autoindex listings

As well as 404ing on files starting with "_", also 404 on files starting
with ".", as these are also private. Except for /.well-known/, because
that's... well known, and should be public.

Because apparently green doesn't show up super-bright with traditional
CMYK printing, so my business card with the green-on-black header
wouldn't have looked great - unless I was willing to pay a lot of money
for special printing.

However, apparently yellow does show up well (probably because it's the
Y in CMYK), and because old-old-school CRTs came in amber-on-black as
well as green-on-black, switching to amber-on-black lets me keep the
same kind of aesthetic while being more print-friendly.

Also, it looks less Matrix-y. On the one hand, that's better because it
looks less derivative. On the other, it's worse, because it doesn't grab
you quite as instinctively as it did before.

I've done it with alternate stylesheets though, so you can still pick
the green colorscheme if you want.

The code is now a bit longer, but it's also a bit clearer. The resulting
HTML is also clearer.