Add wiki link to readme

Description

Adds wiki tutorial link to readme. closes #10

[x] This change isn't already implemented by a pending pull request
[x] This change is a child commit of a reasonably recent commit in the master branch
- Requests need not be a single commit, but should be a linear sequence of commits (i.e. no merge commits in your PR)
[x] All tests pass locally (see the testing section for more info)
[x] All New behaviors or major functional changes have tests