Add link from encryption sentence in "What is Proxmox
Backup Server?" to the Encryption section of the docs.
Also, reword the sentence.
V2:
Clarify that encryption takes place on the client side
Signed-off-by: Dylan Whyte <d.whyte@proxmox.com>
This removes the "Backup Management" first level heading in the docs,
and either uses the sub headings contained within it as first level
headings, or groups previous sections logically under new headings.
The administration-guide.rst file is also removed. Its contents are
instead separated into various files, that relate to their respective
first level heading.
Signed-off-by: Dylan Whyte <d.whyte@proxmox.com>
