This commit uses the new .. zephyr:code-sample-category directive to
categorize code samples across the tree.
Updates existing legacy references to manually defined targets to now
use :zephyr:code-sample-category: role instead.
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
Add a first input sample in the subsys/input directory. This just prints
any input event on the console.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>