and transform to reST.
semantic changes to the content are:
* s/{pve}/`Proxmox Backup`_/g
* changing footnotes to parenthesized notes (did not see footnote use in
the current docs)
* removed the comment about systems setup before the introduction of
p-b-t (which was introduced before pbs)
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
9eb804006c