I think this part is unnecessary.  Minimum setup is simpler than this.  See tryout-jedi.el.

There should be AC manual page that we can link to.  There is a plan to add more AC documentation but the process is very slow.  Ideally, we should contribute to there.
https://github.com/auto-complete/auto-complete/issues/149

That said, if you have tips for AC setup to use it more conferable with Jedi.el, I think that makes sense to have it in Jedi.el document.  If you want to do that, rename the "Extension" section to "Tips" and put your tips in there.  But please make sure to explain what that configuration and link to the corresponding section in the official document (if there is a one).