[#4608] update doc for release 1.8.0
[#4608] update doc for release 1.8.0

minwoo-jung/pinpoint,suraj-raturi/pinpoint,naver/pinpoint,suraj-raturi/pinpoint,barneykim/pinpoint,emeroad/pinpoint,barneykim/pinpoint,jaehong-kim/pinpoint,barneykim/pinpoint,Xylus/pinpoint,suraj-raturi/pinpoint,minwoo-jung/pinpoint,minwoo-jung/pinpoint,denzelsN/pinpoint,naver/pinpoint,koo-taejin/pinpoint,suraj-raturi/pinpoint,jaehong-kim/pinpoint,koo-taejin/pinpoint,emeroad/pinpoint,emeroad/pinpoint,barneykim/pinpoint,minwoo-jung/pinpoint,denzelsN/pinpoint,barneykim/pinpoint,emeroad/pinpoint,Xylus/pinpoint,naver/pinpoint,Xylus/pinpoint,Xylus/pinpoint,minwoo-jung/pinpoint,barneykim/pinpoint,emeroad/pinpoint,jaehong-kim/pinpoint,denzelsN/pinpoint,minwoo-jung/pinpoint,koo-taejin/pinpoint,jaehong-kim/pinpoint,naver/pinpoint,denzelsN/pinpoint,koo-taejin/pinpoint,denzelsN/pinpoint,barneykim/pinpoint,koo-taejin/pinpoint,Xylus/pinpoint,koo-taejin/pinpoint,suraj-raturi/pinpoint,suraj-raturi/pinpoint,emeroad/pinpoint,denzelsN/pinpoint,jaehong-kim/pinpoint,Xylus/pinpoint,Xylus/pinpoint,jaehong-kim/pinpoint,denzelsN/pinpoint,naver/pinpoint