Fix for issue #51
Fix for issue #51

Makes it clear to the user that a file called `setup-passport.js` has
to be created with the contents indicated in step 2 of the nodejs
webapp tutorial. Fixes https://github.com/auth0/docs/issues/51 .

Catografix/docs,Annyv2/docs,sandrinodimattia/docs,jeffreylees/docs,jeffreylees/docs,khorne3/docs,khorne3/docs,yvonnewilson/docs,Catografix/docs,auth0/docs,Annyv2/docs,jeffreylees/docs,Annyv2/docs,hamzawi06/docs,khorne3/docs,Catografix/docs,hamzawi06/docs,hamzawi06/docs,yvonnewilson/docs,auth0/docs,auth0/docs,sandrinodimattia/docs,sandrinodimattia/docs,miparnisari/docs,yvonnewilson/docs