Description of problem:
After change to LVM it might be harder for a user to determine "<vdoBacking>" or "<device>". Help pages of vdo support tools should be updated with an explanation of what to use as a <device> when using LVM to create a VDO volume.

Version-Release number of selected component (if applicable):
vdo-8.2.0.2-1.el9
vdo-support-8.2.0.2-1.el9

How reproducible:
100%

Steps to Reproduce:
1. vdodumpconfig --help
2.
3.

Actual results:
vdodumpconfig - dump the configuration of a VDO volume from its backing
                store.

SYNOPSIS
  vdodumpconfig <vdoBacking>

DESCRIPTION
  vdodumpconfig dumps the configuration of a VDO volume, whether or not
  the VDO is running.
OPTIONS
    --help
       Print this help message and exit.

    --version
       Show the version of vdodmeventd.

Expected results:
Add an example of how to use it with LVMVDO (vdodumpconfig /dev/mapper/vg-vpool0_vdata) and add an explanation that vdodumpconfig should be used with /dev/mapper/*VG-VPOOL*_vdata. 


Additional info: