Added Jupyter Chapter 1.1 (Schnorr Introduction).

[jachiang]

This is the first workshop chapter after an initial setup chapter (chaper 1.0).

An overview of the planned workshop chapters can be found here.

[jachiang]

Ping @elichai for chapter review.

[jachiang]

Update: Imports util.py

[elichai]

First of all wow. you did a lot of work 👍

Second, I hope we can try to simplify some of this. It's going to be pretty hard to get into the details you're getting even into more details and without confusing, the difference between a group order and field order for example is pretty confusing without trying to explain more theoretical parts.

Another thing is quadratic residue.
We are testing a quad residue over y^2=x^3+7 so the quad residue is on y over the field order p.
so either quadratic residue in the curve equation. or just quadratic residue mod p or even just quadratic residue.

[jachiang]

I have now updated this PR and split out the EC-math section to chapter 0.2 (EC math review), as discussed in our call previously.

@elichai Many thanks for your review. Your corrections have been incorporated, with one exception.

@bitschmidty Appreciate your critical review of this chapter and 0.2 ec math review.

[jnewbery]

rebased on master

[jnewbery]

@elichai - thanks for reviewing! I like your suggestions about making ECKey and ECPubKey easier to deal with. Are you able to make a PR to do that? We can add new methods to ECKey and ECPubKey in util.py and then import from there.

[jachiang]

Updated with input from feedback. Incorporates add/mul key class methods in code solutions.

[jnewbery]

I think all feedback in this PR is addressed in #26