Add new recipe (17) by summer student: colourmap subplots

[sadielbartholomew]

This is the first of three recipes created this summer by our first summer student of two, Natalia, at least from the first commit - I have updated it somewhat to show mutliple colour scale categories as sub-plot columns, instead of having each category available from commenting out different parts of the data, which seems more in line with the form of our recipes.

It has been prepared in the form consistent with the existing recipes. Should be nature be self-explanatory. See my comment for the first recipe, #818, for context.

Expected output

[bewithankit]

Hi @sadielbartholomew!

Thank you for this submission, and please extend thanks to Natalia as well. The output plot looks fantastic! Having the perceptually uniform colour maps, NCL enhanced colour maps, and orography/bathymetry colour maps in separate columns clearly demonstrates their distinct characteristics and helps users quickly understand how each type can affect data representation. The use of orography/bathymetry colour scales with air temperature data is a good example of how certain colour maps may not be suitable for certain datasets, as the comments explain.

The overall visual output looks great, and once the remaining files are updated and generated (see my review #818 (comment) of the first recipe), this PR should be good to go. Excellent work on making this visually informative and accessible!

[sadielbartholomew]

Thanks again for your review, @bewithankit. See my latest comment on #818 as to my suggestion for getting these summer student recipe PRs (including the three I will put up in the next few days to complete the set, too) merged. I have updated this PR to add to the recipe_list.txt so as fr as I am concerned, this is ready to merge (assuming my plan from the comment on #818 as to when to add the built objects to update the docs).

[sadielbartholomew]

Given how busy Ankit is with his PhD we have agreed I can merge this without second review. At release time I will enact the plan I outlined above:

let me suggest that I add all five recipes via PRs like this one, with the Python script and addition to the recipe_list.txt, then I do a final PR where I add all of the built material from those five to the repo finally, show they show up on the site

So, merging, and there will eventually be a follow-on PR to get all the new recipes built and included.