DMR and Corner Plot example notebook

[aangress]

Added notebook that shows users how to extract simple DMR and corner plots for COOLEST .tar.gz files. Includes two example COOLEST files and expected plots.

[aymgal]

Hi @aangress , thanks for this PR. I have a few comments:

• For example notebooks it would be better to follow the style and organization already in place, namely: renaming the notebook to follow the names of other notebooks, as well as updating the index.md in the docs/notebooks directory.
• Why not moving your handy dmr_corner() function into the package itself? Perhaps incoolest.api.plot_util.
• Adding fig.tight_layout() before showing / saving the figure can improve the spacing of the subplots.
• Is the tutorial.tar.gz really useful?
• Would you mind adding a docstring to the function please? In the same format is in e.g. [this code](

  COOLEST/coolest/api/plotting.py

  Line 36 in a445e54

  """Create pyplot panels from a lens model stored in the COOLEST format.

  ("Numpydoc" style)

Let me know if something is unclear!

[aangress]

Hey @aymgal, thanks for all the good comments! I just reorganized and moved a bunch of stuff around according to your suggestions, so let me know what you think! Also, you're right about the tutorial.tar.gz file--it was a bit unnecessary.

[aymgal]

@aangress Thank you for the changes! However it seems there is a conflict that prevents the merge. Did you pull the latest version of the main branch? Maybe this is the reason. Let me know how this goes, and hopefully we are able to merge. We will then do the same for your PR #71 .

[aangress]

@aymgal Yeah, looks like it was just small conflicts because I opened all the PRs at the same time, and they all made edits to plot_util. The plot title branch was already merged into the main branch by the time we got here. I think this should be a clean merge now. The same should happen with the normalization PR; once this is merged I'll fix that up as well. Sorry about the messiness--I'm new to Github!

[aymgal]

@aangress No worries! Looks good so I merge this one, then you can check things and proceed similarly for the other PRs 👍