docs: update rtd documentation for altcloud

This bug was originally filed in Launchpad as [LP: #1968789](https://bugs.launchpad.net/cloud-init/+bug/1968789)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = None

date_created = 2022-04-12T20:46:24.022823+00:00

date_fix_committed = None

date_fix_released = None

id = 1968789

importance = undecided

is_complete = False

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1968789

milestone = None

owner = chad.smith

owner_name = Chad Smith

private = False

status = triaged

submitter = chad.smith

submitter_name = Chad Smith

tags = ['bitesize']

duplicates = []

_Launchpad user **Chad Smith(chad.smith)** wrote on 2022-04-12T20:46:24.022823+00:00_

Update "read the docs" content at
doc/rtd/topics/datasources/altcloud.rst

Ensure it correctly represents behavior and configuration options as used in:
cloudinit/sources/DataSourceAltCloud.py

Example format/style should be something like:

doc/rtd/topics/datasources/ec2.rst

Specifically, these docs need to also include discussion of seed directory setup in /var/lib/cloud/seed/*.

Start with doc/rtd/topics/datasources/altcloud.rst and compare it with cloudinit/sources/DataSourceAltCloud.py. Use doc/rtd/topics/datasources/ec2.rst as the style reference. Done means the AltCloud documentation accurately covers its behavior, configuration options, and seed directory setup under /var/lib/cloud/seed/*.

Written by the indexing model from the issue text.