Add to our documentation some install % setup tips

[perki]

Ubuntu 20
“systemd-resolved” is using port 53 and need to be deactivated
See: https://www.qualityology.com/tech/ubuntu-port-53-already-in-use-how-to-free-the-dns-port/

Ubuntu 22
"docker" install with apt-get is package into "snap" and does not have access to files
either find a way to setup snap or install docker without apt-get

On Google cloud
We faced an “error” with the binding of public IP (we suspect GCE to have different public machine IP than the local one)
It was solved by changing the SINGLE_MACHINE_PUBLIC_INTERFACE_IP_ADDRESS value
to 0.0.0.0 in the platform template (${PRYV_CONF_ROOT}/config-leader/conf/platform.yml)