Add Ostinato Time Series Consensus Motif Notebook Reproducer

[seanlaw]

Reproduce the ostinato algorithm and one of the figures from the original paper in a Jupyter notebook. Below is a rough checklist:

• Fork the STUMPY repo
• Clone your own forked repo
• Create a new ostinato branch
• Add a new Jupyter notebook in the stumpy.git/docs/ directory. In the docs directory you should see a whole bunch of notebooks with Tutorial_<name>.ipynb names. Let's call it Tutorial_Ostinato.ipynb or Tutorial_Consensus_Motif (I trust your judgement) and start developing the code and figure reproduction there. Feel free to check out any of the existing notebooks in that directory for reference but also do not hesitate to ask me.
• In the notebook, add a clear def ostinato function that is consistent with the published algorithm
• download data that reproduces a figure from the original paper
• Reproduce one of the figures from the original paper
• Once you have an ostinato function defined in your notebook and an example that reproduces one of the major figures in the paper then commit that to your forked repo branch and submit a PR for review. Alternatively, feel free to submit a PR for review as "work-in-progress" (WIP) if it is incomplete but that you want me to provide any feedback on direction or if you have any questions in general. In other words, there is no need to work in complete isolation. I am here to help!

Note that this notebook reproducer example serves as a rough prototype for discussion and should be completely separate from incorporating a new feature into STUMPY as in #277 .

[seanlaw]

@DanBenHa This is here for your reference. Let me know what you think