squashed merge of #54: flesh out namer documentation
squashed merge of #54: flesh out namer documentation

flesh out namer documentation and other doc tweaks

denverwilliams/linkerd,pawelprazak/linkerd,linkerd/linkerd,hhtpcd/linkerd,BuoyantIO/linkerd,pawelprazak/linkerd,denverwilliams/linkerd,hhtpcd/linkerd,BuoyantIO/linkerd,denverwilliams/linkerd,linkerd/linkerd,hhtpcd/linkerd,linkerd/linkerd,denverwilliams/linkerd,pawelprazak/linkerd