clarify building confd from source
clarify building confd from source

Some users that are new to Go have been confused with the instructions on how to get started.
Hopefully this clears up the confusion.

kelseyhightower/confd,kelseyhightower/confd,Fitbit/confd,okushchenko/confd,blippar/confd,okushchenko/confd,bacongobbler/confd,rancher/confd,bacongobbler/confd,Fitbit/confd,rancher/confd,blippar/confd