Create E2E nightly / pr test for our example

[PaliC]

We need to make sure our example doesn't get randomly broken. We should make an E2E test to ensure that it actually works!

We just need to go through the readme. We save the necessary files in a folder called multipy/examples, then we just need to reproduce the examples as a job using github actions in a file called multipy/.github/workflows/test_example.yaml. You can look at the other workflows to get an idea of how to create this one!