* Logically organize the Whonix-related pages
* Move the VPN page to /configuration/
* VPNs are used for more than just privacy, and many VPN setups and
services either can't or don't claim to provide privacy.
* Remove `/privacy/` from URLs
* These directory names are just for organizing the source pages,
*unless* an actual page resides there. Since there is no
/doc/privacy/ page, it's unnecessary and misleading to have this in
the URLs. It also breaks uniformity, since none of the other pages
have their informal group name in their URL (again, unless there's
a page with that name).
Explanation: All of our other pages consist of an .md file with
the name (or a suitably similar name) of that page. This commit
renames `configuration/salt/index.md` to `configuration/salt.md`
so that it will follow the organization of the other pages.
