[DOCS] Show possible kwargs in either docstring or website

[GuillermoFidalgo]

It's not very obvious to the user what the possible kwargs could be for things like plot_ratio and plot_pull just by looking at the documentation page.

It might be useful to list those that are not standard or at least mention something like
**kwargs – Keyword arguments passed to underlying matplotlib function - pcolormesh. (example from hist2dplot)
This example in particular led me to find a very useful solution to easily change the scale of the colors to log by using the norm= "log" kwarg.

[GuillermoFidalgo]

It is also not obvious what possible str arguments are allowed for functions like plot_ratio as a valid obj for other
other : hist.BaseHist | Callable[[np.typing.NDArray[Any]], np.typing.NDArray[Any]] | str,
or for ax_dict: dict[str, matplotlib.axes.Axes]

I just happen to guess that "gauss" is a valid argument for other