Remove README.volumes as it was specific to thunar-vfs.

docs/README.volumes

-The Thunar Volume Manager
-=========================
-
- The Thunar-VFS library contains an abstract interface to volume managers
- and implementations of this interface for some platforms (currently only
- FreeBSD and Linux with HAL is known to work properly).
-
- Using this abstract interface (in fact the platform specific implementations
- of the interface), Thunar is able to display mounted and mountable volumes
- in the shortcuts pane, and allows the user to mount or eject/unmount these
- volumes from the context menu. In addition, if the user double-clicks a
- volume in the shortcuts pane (or requests to open the shortcut in a new
- window), Thunar will first try to mount the volume if it's not already
- mounted.
-
- Unfortunately, this functionality is currently only available to BSD users.
- I'm looking for people to provide implementations of ThunarVfsVolume and
- ThunarVfsVolumeManager (see thunar-vfs-volume.h) for other platforms. If
- you need a starting point, you should have a look at the FreeBSD implemen-
- tation in thunar-vfs-volume-freebsd.c, it's a bit tricky when it comes to
- details, but it should give you the basic idea.
-
-
- Notes for FreeBSD users
- ------------------------
-
-  FreeBSD offers a really nice option, which allows regular users to mount
-  devices on every folder owned by the user. It is very handy for a single
-  user desktop system.
-  You'll need to enable the vfs.usermount option for this to work:
-
-   # sysctl -w vfs.usermount=1
-
-  Afterwards, just change the owner of the mount points for removable
-  devices to your user id, i.e.
-
-   # chown benny /mnt/dvd
-   # chown benny /mnt/cdrw
-
-  and you will be able to mount and unmount your DVD and CD-RW in Thunar.
-
-  In order to be able to eject removable devices, you will need to install
-  the eject utility from the sysutils/eject port.
-
-
- Notes for Linux users
- ---------------------
-
-  On Linux platforms, Thunar requires HAL 0.5 or better to provide information
-  about volumes.
-
-  To be able to eject dics, you will need the eject utility program.