Update es.json
Update es.json

Missing translation on 'How to npm'
denysdovhan/nodeschool.github.io,nodeschool/nodeschool.github.io,jthoms1/nodeschool.github.io,nodeschool/nodeschool.github.io,nodeschool/nodeschool.github.io,jthoms1/nodeschool.github.io,denysdovhan/nodeschool.github.io,denysdovhan/nodeschool.github.io,jthoms1/nodeschool.github.io