Missing Nymea:core basic details

Im new here and tried, the process to setup a headless RPI with nymea:core
And there is not place pointing ssh user and password, and since is different from RPI OS, i think is important to be added that
in the doc
Sorry if this info is in some obvious place that i skipped

Indeed, thanks for pointing this out. Added it to the website (so far only on preview.nymea.io which is the staging server)