Add README.md for Benchmark test.
Add README.md for Benchmark test.

wangkirin/oct,hustcts/ocp-testing,hqhq/oct,Tiesheng/oct,ChengTiesheng/oct,hqhq/oct,wking/rkt-oci,Tiesheng/oct,liangchenye/oct,liugenping/oct,liugenping/oct,hustcts/ocp-testing,zenlinTechnofreak/oct,huawei-openlab/oct,ChengTiesheng/oct