Write notebook with hit-and-miss example

[redeboer]

As a follow-up to #1, it would be cool to have a small example of hit-and-miss (accept-reject) sampling in Python (NumPy). I think the two examples that @H178561 worked out are nice:

1. $\sqrt{1-x^2}$, where you know the maximum is just 1, and you can apply a uniform sampling strategy.
2. Some function where (ideally) you do not know what the maximum is, so that you have to use a smart strategy to find that maximum numerically as you are sampling.
   It's a bit hard to come up with a simple example where it is hard to find the maximum, but you can also just take two Gaussians and pretend that you don't know the maximum. The idea is the same.

[redeboer]

@Niheaa, CONTRIBUTING.md offers a simple starting guide. But in theory you don't even need git: spin up rub-ep1.github.io/lite, play around in a new notebook there, download it, and upload it through a pull request to this repo.

@shenvitor wrote an example for amplitude analysis. The idea is the same, only the "domain" generator is different (phase space). You still have a while statement that checks if a new maximum is hit:
https://compwa.github.io/report/033/index.html#final-state-four-momenta