readme: remove broken link
readme: remove broken link

closes #6
fmoliveira/workshop,superphung/workshop,gogobook/workshop,fmoliveira/workshop,fmoliveira/workshop,superphung/workshop,dk0104/workshop,gogobook/workshop,gogobook/workshop,koajs/workshop,superphung/workshop,koajs/workshop,dk0104/workshop,dk0104/workshop,koajs/workshop