Documentation of sysfs interface should be in ABI in the first place.
This moves relevant part of documentation and mentions where to look for
it.
Fix trivial typos whilst we are at it.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NJacek Anaszewski <j.anaszewski@samsung.com>

Add oneshot trigger to blink a led with configurale parameters via
sysfs.
Signed-off-by: NFabio Baltieri <fabio.baltieri@gmail.com>
Cc: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: NBryan Wu <bryan.wu@canonical.com>