fix README file
fix README file

kauffecup/alchemyapi_node,AlchemyAPI/alchemyapi_node,pcchiu524/mayday_alchemy,JFerguson576/alchemyapi_node,acm-nonsense/467-nonsense-impl1,K-Phoen/node-alchemyapi,acm-nonsense/467-nonsense-impl1,digitalartcrew/alchemyapi_node,CristinaFoltea/alchemyapi_node,weitingchou/alchemy_demo,steveherschleb/sdk_javascript,tobha/alchemynode,vinh3928/alchemyapi_node