Update Tutorial.md
Update Tutorial.md

Add step 0): Get the code
ryi06/inferelator_ng,simonsfoundation/inferelator_ng,simonsfoundation/inferelator_ng,AaronWatters/inferelator_ng,simonsfoundation/inferelator_ng,ryi06/inferelator_ng,AaronWatters/inferelator_ng,AaronWatters/inferelator_ng