doc: configuration: fix docker strategy documentation

In an initial version of the patch series, the strategy was called
DockerShellStrategy. But that was changed before the PR was merged. So
adjust the documentation to the actual existing DockerStrategy.

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Author: Bastian-Krause

doc/configuration.rst

@@ -2685,35 +2685,30 @@ to transition to the shell state:
 this command would transition from the bootloader into a Linux shell and
 activate the ShellDriver.
 
-DockerShellStrategy
-~~~~~~~~~~~~~~~~~~~
-A DockerShellStrategy has three states:
+DockerStrategy
+~~~~~~~~~~~~~~
+A DockerStrategy has three states:
 
 - unknown
-- off
-- shell
+- gone
+- accessible
 
 
-To transition to the shell state:
+In order to use the DockerStrategy via labgrid as a library and transition to
+the ``accessible`` state:
 
 ::
 
    >>> from labgrid import Environment
    >>> e = Environment("local.yaml")
    >>> t = e.get_target("main")
-   >>> s = t.get_driver("DockerShellStrategy")
-   >>> s.transition("shell")
-
+   >>> s = t.get_driver("DockerStrategy")
+   >>> s.transition("accessible")
 
 These commands would activate the docker driver which creates and starts
 a docker container. This will subsequently make `NetworkService`_ instance(s)
 available which can be used for e.g. SSH access.
 
-Note: Transitioning to the "off" state will make any `NetworkService`_
-instance(s) unresponsive - which may in turn invalidate SSH connection
-sharing. Therefore, during automated test suites, refrain from transitioning
-to the "off" state.
-
 Reporters
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