* Upgrade alpine to 3.15
* Add executability test to entrypoint for too old dockers
Signed-off-by: Andrew Thornton <art27@cantab.net>
* Update docker/rootless/usr/local/bin/docker-entrypoint.sh
Co-authored-by: zeripath <art27@cantab.net>
* docker: rootless image
* improve docs + remove check for write perm on custom
* add more info on ssh passtrough
* Add comment for internal ssh server in container config