docs: better documentation of dsmode=local vs dsmode=net

This bug was originally filed in Launchpad as [LP: #1991677](https://bugs.launchpad.net/cloud-init/+bug/1991677)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = None

date_created = 2022-10-04T14:34:04.972138+00:00

date_fix_committed = None

date_fix_released = None

id = 1991677

importance = medium

is_complete = False

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1991677

milestone = None

owner = chad.smith

owner_name = Chad Smith

private = False

status = triaged

submitter = chad.smith

submitter_name = Chad Smith

tags = []

duplicates = []

_Launchpad user **Chad Smith(chad.smith)** wrote on 2022-10-04T14:34:04.972138+00:00_

Per https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1991261 there is confusion about the impact of dsmode=net vs local on cloud-init runtime.

This is a request for improved/conspicous general datasource documentation of dsmode settings and the impact to cloud-init configuration.

The only current doc references we have pointing to dsmode behavior are at specific datasources:
1. https://cloudinit.readthedocs.io/en/latest/topics/datasources/opennebula.html?highlight=dsmode#datasource-configuration

2. https://cloudinit.readthedocs.io/en/latest/topics/datasources/configdrive.html?highlight=dsmode#keys-and-values