ja: rest_qos: Fix typos

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: Minoru TAKAHASHI <takahashi.minoru7@gmail.com>
en: rest_qos: Add English description for QoS Apps

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: Minoru TAKAHASHI <takahashi.minoru7@gmail.com>