Documentation and Feature request: Automatic xarray plot layout and control

#### Is your feature request related to a problem? Please describe.
The default axis layout algorithm is not described in the docs, and there is an unexpected inversion of the coordinate list which breaks any intuitive thoughts on how the axis layout could have been determined.

Additionally, there's a very helpful attribute-based determination of the axes that needs documentation.

However, I do not understand why this solution was only implemented for gridded data? I think it can be helpful in all cases?

#### Describe the solution you'd like

* Docs: A clear and concise example on how to control axis layout for xarray plots.
* Feature request: Implement attribute lookup for all xarray plots

#### Additional context
https://discourse.holoviz.org/t/hvplot-and-xarray-what-determines-the-default-axes-layout/2933/6