README.md: add custom HTTP Headers example.
README.md: add custom HTTP Headers example.

not001praween001/request,longwenjunjie/request,HAKASHUN/request,motopia/request,faradayio/request,request/request,xiwc/request,calibr/request,NewGyu/request,wakermahmud/request,neo-z/request,manishnakar/request,lalitkapoor/request,watson/request,blabno/request,rbramwell/request,request/request,h1bomb/request,robu3/request,HAKASHUN/request,niklabh/request,cvibhagool/request,sean3z/request,h1bomb/request,longwenjunjie/request,seegno-forks/request,linalu1/request,jzaefferer/request,Codelegant92/request,kmulvey/request,wangchi/request,faradayio/request,ryanwholey/request,udp/request,kmulvey/request,Jonekee/request,chaoliu/request,xiwc/request,nishant8BITS/request,LoicMahieu/request,manishnakar/request,Codelegant92/request,xtidt/request,LoicMahieu/request,beni55/request,paulomcnally/request,wangchi/request,zodsoft/request,not001praween001/request,Jonekee/request,zodsoft/request,nishant8BITS/request,simov/request,robu3/request,lxe/request,calibr/request,niklabh/request,djchie/request,Prasanna-sr/request,linalu1/request,djchie/request,motopia/request,phillipj/request,pho3nixf1re/request,wakermahmud/request,cvibhagool/request,Prasanna-sr/request,zhouweiming/request,neo-z/request,mvnnn/request,ryanwholey/request,phillipj/request,sean3z/request,kublaj/request,IbpTeam/node-request,rbramwell/request,watson/request,seegno-forks/request,jzaefferer/request,IveWong/request,lxe/request,IveWong/request,chaoliu/request,pho3nixf1re/request,Aloomaio/request,paulomcnally/request,zhouweiming/request,blabno/request,simov/request,pablobrady/request,kevinburke/request,mvnnn/request,MofeLee/request,jsifuentes/request,NewGyu/request,beni55/request,jsifuentes/request,czardoz/request,kevinburke/request,udp/request,lalitkapoor/request,whembed197923/request,kublaj/request,xtidt/request,IbpTeam/node-request,MofeLee/request,czardoz/request,Aloomaio/request,pablobrady/request,whembed197923/request