Cleanup recipe headers before the release

[mattiarighi]

Make recipe headers uniform and fix a few typos.

[mattiarighi]

@katjaweigel I renamed recipe_martin2018grl.yml to recipe_martin18grl.yml for consistency with our file naming convention.

[bouweandela]

You lost acknow_project here

[bouweandela]

Though that is actually not a reference, but a request to acknowledge, so maybe we need to think a bit about how to improve this in the future

[mattiarighi]

acknow_project was introduced for cases where no other references were available, which is not case here.

[bouweandela]

That's probably never the case, because all our recipes are based on scientific work, right? Only the example recipes wouldn't have references.

[mattiarighi]

Actually there are 5 recipes without an actual reference: recipe_consecdrydays.yml, recipe_ocean_Landschuetzer2016.yml, recipe_ocean_multimap.yml, recipe_shapeselect.yml and recipe_spei.yml.

[bouweandela]

Maybe references just need to be added?

[mattiarighi]

Maybe yes, but not all our diagnostics are based on published work, or the paper is not yet ready.

[bouweandela]

I think it would be fine to have no reference if no reference is available.

[katjaweigel]

For recipe_spei.yml there are the references vicente10jclim and mckee93proc given inside the two diagnostics it calls. But they are references for the SPEI and SPI indices used, not for the histograms of them plotted by the recipe, this is probably why they are not there at the moment.