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>
Clean up documentation pages for the new perf tool
as they contained several typos, grammar errors, and
duplicated content between main doc page and sample
page
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
