Add README.md for the OP benchmark system, representing how to use 'tests/run.sh'

[AshburnLee]

A README.md file has uploaded, a image will be upload later

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[paddle-bot-old[bot]]

✅ This PR's description meets the template requirements! Please wait for other CI results.

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7 out of 8 committers have signed the CLA.

:white_check_mark: Xreki
:white_check_mark: donproc
:white_check_mark: gfwm2013
:white_check_mark: luotao1
:white_check_mark: hysunflower
:white_check_mark: ccmeteorljh
:white_check_mark: AshburnLee
:x: Zhang Ting

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