There is a bit more out there including Aurelien's excellent write up
and older Debian images here:

  https://www.aurel32.net/info/debian_arm_qemu.php
  https://people.debian.org/~aurel32/qemu/armel/

However the web is transitory and git is forever so lets add something
to the fine manual.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20210202134001.25738-16-alex.bennee@linaro.org>