`cmocean.tools.print_colormaps` snippet in the docs raises an error

Hello! I love your work, this is my favorite set of colormaps.

Today I wanted to run some code from the docs:

import cmocean

cmaps = cmocean.cm.cmap_d
cmocean.tools.print_colormaps(cmaps)

and it produces the following exception and traceback:

Traceback (most recent call last):
  File "/home/mfisher/Projects/_test/extend-colormaps-js/test.py", line 4, in <module>
    cmocean.tools.print_colormaps(cmaps)
  File "/home/mfisher/Projects/_test/extend-colormaps-js/.pixi/envs/default/lib/python3.12/site-packages/cmocean/tools.py", line 25, in print_colormaps
    rgbtemp = cmap(np.linspace(0, 1, N))[np.newaxis, :, :3][0]
              ^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'str' object is not callable

The issue appears to be here:

https://github.com/matplotlib/cmocean/blob/59c35002c3aa5296b65d9646e52604c627441eb6/cmocean/tools.py#L23

We loop over the cmaps object, which is a dictionary of colormap name keys to colormap object values in this invocation, but the function expects the object to be a list of colormap objects.

So the docs could be updated to:

import cmocean

cmaps = cmocean.cm.cmap_d
cmocean.tools.print_colormaps(cmaps.values())

But after running this code I don't see the output files!

Inizia con l’esempio di capabilities collegato nell’issue e con cmocean/tools.py intorno alla riga 23; esegui lo snippet documentato e verifica come print_colormaps gestisce il proprio input e scrive l’output. Aggiorna l’esempio nella documentazione in modo che non generi più l’errore segnalato e chiarisci o verifica dove dovrebbero comparire i relativi file di output.