doc: update release notes for hns3
doc: update release notes for hns3

Add TM(Traffic Management) feature with hns3 in release notes.
It includes:
1. configure port's peak rate with PF
2. configure TC's peak rate with PF

Fixes: c09c7847d892 ("net/hns3: support traffic management")
Cc: stable@dpdk.org

Signed-off-by: Lijun Ou <4f660ba6ca3aa3bf060789cece061ff7ba22d4fe@huawei.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk