cloud init documentation ?

From: mike tancsa <mike_at_sentex.net>
Date: Wed, 24 Jul 2024 19:08:41 UTC
I gave the cloud-init image a spin, but beyond adding some users, I am 
not able to get packages added or even runcmd or bootcmd to execute.   
This is using the FreeBSD-14.1-RELEASE-amd64-BASIC-CLOUDINIT-zfs.raw 
image from the FreeBSD download directory.  Where can I find 
documentation on what is supported ?

Is there also a way to test the config beyond deploying and seeing if it 
works or not ?

     ---Mike