Update process

[dalbert2]

Not really an issue other than perhaps a documentation issue:

With the release of Debian 11, the repository changed from stable to oldstable and apt will not update from it without an additional command line option, so the update commands look like this:
apt update --allow-releaseinfo-change
apt upgrade

Thank you so much for putting this together Supratim! I thought I was going to have to recycle my old pogoplug mobile when ArchLinux ARM unceremoniously dropped support for the armv5 architecture.