Datatree docs should mention that assigning to `.dataset` is allowed

[TomNicholas]

What is your issue?

See xarray-contrib/datatree#312, fyi @flamingbear

[flamingbear]

Well, .dataset anyway from the outcome of #9458

[adam2392]

Hey I've always found Xarray useful, so I wanted to start understanding the internal codebase more. Happy to take this on if no one else is tackling it?

[TomNicholas]

That would be great @adam2392 ! The implementation of the property and setter that needs documenting is here

xarray/xarray/core/datatree.py

Line 601 in 7fd572d

def dataset(self) -> DatasetView:

The fact you can assign to this property should probably be documented

1. In the docstring of the property
2. here https://docs.xarray.dev/en/stable/user-guide/data-structures.html#datatree-contents
3. and in a new section under here https://docs.xarray.dev/en/stable/user-guide/hierarchical-data.html#tree-contents