[Doc]: logo example should include dark option and have names

[jklymak]

Documentation Link

https://github.com/matplotlib/matplotlib/blob/main/galleries/examples/misc/logos2.py

Problem

We now have a dark version that should be in the logo example as a toggle.

The logo example should have "logo_light.svg" and "logo_dark.svg" somewhere in the text so its searchable by the name of the files that get used in the site logo.

See matplotlib/mpl-sphinx-theme#62

[kindler-king]

Hello @jklymak, I just came across this issue and looked at the links you shared.
Do we want to add a new example altogether to highlight the creation of the dark mode logo too ?
Or should just having textual reference to suggest the existence of a dark themed logo do the trick?

[jklymak]

I'd have the example make both logos.

[kindler-king]

Hello @jklymak , is this what you had in mind?
I have added a new parameter to the make_logo method called 'mode' which can be used to generate 2 different kinds of logo both the "logo_light.svg" and "logo_dark.svg" mainly because the hexcode color for the logo_light.svg was hard coded in the example.

We can incorporte this new example as seen in the screenshot to the matplotlib logo example, if you feel this seems good enough.