Augment cookie example in README for multiple cookies
Augment cookie example in README for multiple cookies

This change updates the README to show how to pass multiple cookies.
hoatle/httpie,keita1314/httpie,gnagel/httpie,meigrafd/httpie,MiteshShah/httpie,bright-sparks/httpie,guiquanz/httpie,GrimDerp/httpie,fontenele/httpie,ardydedase/httpie,normabuttz/httpie,konopski/httpie,fritaly/httpie,alfcrisci/httpie,lingtalfi/httpie,bitcoinfees/two1-httpie,normabuttz/httpie,jakubroztocil/httpie,danieldc/httpie,rgordeev/httpie,lk1ngaa7/httpie,zerin108/httpie,vietlq/httpie,konopski/httpie,tylertebbs20/Practice-httpie,kevinlondon/httpie,paran0ids0ul/httpie,avtoritet/httpie,HackerTool/httpie,jkbrzt/httpie,tylertebbs20/Practice-httpie,gnagel/httpie,JPWKU/httpie,keita1314/httpie,bgarrels/httpie,Batterfii/httpie,alexeikabak/httpie,MiteshShah/httpie,paran0ids0ul/httpie,aredo/httpie,rschmidtz/httpie,zerodark/httpie,Batterfii/httpie,insionng/httpie,fritaly/httpie,rgordeev/httpie,jkbrzt/httpie,whitefoxx/httpie,codingjoe/httpie,mblayman/httpie,sofianhw/httpie,ardydedase/httpie,kevinlondon/httpie,a-x-/httpie,alfcrisci/httpie,lk1ngaa7/httpie,whitefoxx/httpie,meigrafd/httpie,a-x-/httpie,HackerTool/httpie,saisai/httpie,bgarrels/httpie,kaushik94/httpie,Bogon/httpie,wandec/first,jcrumb/httpie,rusheel/httpie,marklap/httpie,hoatle/httpie,PKRoma/httpie,fontenele/httpie,vietlq/httpie,jakubroztocil/httpie,jcrumb/httpie,mblayman/httpie,PKRoma/httpie,aredo/httpie,danieldc/httpie,Bogon/httpie,GrimDerp/httpie,saisai/httpie,alex-bretet/httpie,avtoritet/httpie,codingjoe/httpie,jkbrzt/httpie,insionng/httpie,bright-sparks/httpie,bitcoinfees/two1-httpie,marklap/httpie,alex-bretet/httpie,alexeikabak/httpie,JPWKU/httpie,jakubroztocil/httpie,guiquanz/httpie,zerin108/httpie,sofianhw/httpie,zerodark/httpie,chaos33/httpie,rschmidtz/httpie,lingtalfi/httpie,rusheel/httpie