Updated readme for issues API
Updated readme for issues API

ludovicderochethales/node-github,meetearnest/node-github,cbargren/github-xhr,AkashSC/MyRepoDOMO,eistrati/node-github,F1LT3R/node-github,trektech/test1,codeschool/node-github,Phanatic/node-github,kaizensoze/node-github,jamestalmage/node-github,tempbottle/node-github,Gerhut/node-github,onesfreedom/node-github,apiaryio/node-github,kstarsinic/node-github,ekristen/node-github,reviewninja/node-github,blamattina/node-github,Dica-Developer/github-js,kaizensoze/github4,dfarr/node-github