Someone pointed that to me the other day, took me 5 hours 45 minutes to do 100-110
Add-on is called ConsLegion, here is the link
https://mods.curse.com/addons/wow/conslegion.
Once you pick your zone, it literally tells you everything to do, go there, go here, pick 3 quests, go over there, pick 2 quest, kill x,y,z, finish this here, in the most optimal fashion.
Figured it might help some people here that dread leveling an alt.