docs: remove aufs and legacy overlay

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

docs/extend/plugins_graphdriver.md

@@ -25,7 +25,7 @@ advisory: experimental
 
 Docker graph driver plugins enable admins to use an external/out-of-process
 graph driver for use with Docker engine. This is an alternative to using the
-built-in storage drivers, such as aufs/overlay/devicemapper/btrfs.
+built-in storage drivers, such as overlay2.
 
 You need to install and enable the plugin and then restart the Docker daemon
 before using the plugin. See the following example for the correct ordering

docs/reference/commandline/dockerd.md

@@ -323,7 +323,7 @@ $ docker -H tcp://127.0.0.1:2375 pull ubuntu
 ### Daemon storage-driver
 
 On Linux, the Docker daemon has support for several different image layer storage
-drivers: `aufs`, `devicemapper`, `btrfs`, `zfs`, `overlay`, `overlay2`, and `fuse-overlayfs`.
+drivers: `overlay2`, `fuse-overlayfs`, `btrfs`, `zfs`, and `devicemapper`.
 
 `overlay2` is the preferred storage driver for all currently supported Linux distributions,
 and is selected by default. Unless users have a strong reason to prefer another storage driver,