README: update currently supported features

The README is often the first thing people look at, so it should reflect
the state of the projekt accurately. So try to describe the set of
labgrid's features on high level.

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

Author: Bastian-Krause

README.rst

@@ -24,12 +24,17 @@ background information.
 
 It currently supports:
 
-- pytest plugin to write tests for embedded systems connecting serial console or
-  SSH
 - remote client-exporter-coordinator infrastructure to make boards available
   from different computers on a network
-- power/reset management via drivers for power switches or onewire PIOs
-- upload of binaries via USB: imxusbloader/mxsusbloader (bootloader) or fastboot (kernel)
+- pytest plugin to write automated tests for embedded systems
+- CLI and library usage for development and automation
+- interaction with bootloader and Linux shells on top of serial console or SSH
+- power/reset management via drivers for power switches
+- upload of binaries and device bootstrapping via USB
+- control of digital outputs, SD card and USB multiplexers
+- integration of audio/video/measurement devices for remote development and
+  testing
+- Docker/QEMU integration
 
 While labgrid is currently used for daily development on embedded boards and for
 automated testing, several planned features are not yet implemented and the APIs