Merge branch 'master' of https://github.com/anyRTC/ArRTCWebSDK
# Conflicts:
# .gitignore
# Demo/assets/bootstrap.bundle.min.js
# Demo/assets/bootstrap.min.css
# Demo/assets/index.css
# Demo/assets/jquery-3.4.1.min.js
# Demo/audioMixingAndAudioEffect/HeroicAdventure.mp3
# Demo/audioMixingAndAudioEffect/audio.mp3
# Demo/audioMixingAndAudioEffect/audioMixingAndAudioEffect.js
# Demo/audioMixingAndAudioEffect/index.css
# Demo/audioMixingAndAudioEffect/index.html
# Demo/basicLive/basicLive.js
# Demo/basicLive/index.css
# Demo/basicLive/index.html
# Demo/basicVideoCall/basicVideoCall.js
# Demo/basicVideoCall/index.css
# Demo/basicVideoCall/index.html
# Demo/index.html
# Demo/recordingDeviceControl/index.css
# Demo/recordingDeviceControl/index.html
# Demo/recordingDeviceControl/recordingDeviceControl.js
# Demo/shareTheScreen/index.css
# Demo/shareTheScreen/index.html
# Demo/shareTheScreen/shareTheScreen.js
# README.cn.md
# README.md
add displayCallStats demo， update SDK
