Add a guide for moving from 1.xx to 2.0
Add a guide for moving from 1.xx to 2.0

blublud/networkx,chrisnatali/networkx,chrisnatali/networkx,OrkoHunter/networkx,goulu/networkx,aureooms/networkx,beni55/networkx,JamesClough/networkx,yashu-seth/networkx,chrisnatali/networkx,wasade/networkx,tmilicic/networkx,ionanrozenfeld/networkx,cmtm/networkx,jcurbelo/networkx,SanketDG/networkx,ionanrozenfeld/networkx,andnovar/networkx,blublud/networkx,michaelpacer/networkx,aureooms/networkx,Sixshaman/networkx,ltiao/networkx,aureooms/networkx,ionanrozenfeld/networkx,NvanAdrichem/networkx,jfinkels/networkx,blublud/networkx