Error in the router tutorial

[butla]

It's a small thing, but the routing tutorial still has the problem with

# external.py
import hug

import external

when it should import internal, while the version in docs of the core hug repository is OK.

[cag]

Also, from @ctwardy

I also noticed two simple typos in the main text:

• extreamly -> extremely
• convience -> convenience
  I tried a quick git clone but I don't think these docs are in git, and something wasn't right with my environment, so I'm just filing this ticket.

hugapi/hug#439

[butla]

@cag Thanks for finding the connection :)