Add some initial documentation detailing what acer-wmi is, and how to use
it. Update the Kconfig entry with a reference to the documentation.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLen Brown <len.brown@intel.com>