update kitchen sink pages

[drammock]

closes #2038

[drammock]

doc build looks good: https://pydata-sphinx-theme--2190.org.readthedocs.build/en/2190/examples/kitchen-sink/images.html

top few images are weirdly aligned, but that's not our theme's fault: https://sphinx-themes.org/sample-sites/default-alabaster/kitchen-sink/images/

[gabalafou]

Unfortunately, the accessibility test failures are real. The update to the kitchen sink brought in some new links. These new links do not meet color contrast thresholds (WCAG AA). Some screen shots below:

Light mode

In light mode, the link color is #0a7d91.

(same goes for versionchanged, deprecated, and versionremoved admonitions)

Dark mode

In dark mode, the link color is #3fb1c5 and it has enough contrast with all of the admonition backgrounds except one.

[trallard]

OK I am going to approve and merge this PR.
The colour contrast issues can be fixed separately (I already opened an issue).

[drammock]

hooray for the kitchen sink actually revealing some legitimate issues! I'm always grumpy about all the spurious API docstring warnings that it causes, it's nice for it to "earn its keep" for a change.