Documentation regarding optional Orderable Inheritance for Inline models

[bmihelac]

The documentation states that inline models need to inherit from Orderable.

I have tested an inline model that does not inherit from Orderable and it works as expected—there are no buttons to reorder, but everything functions properly.

Pertinent section of the Wagtail docs

https://docs.wagtail.org/en/stable/topics/pages.html#inline-models
https://github.com/wagtail/wagtail/blob/main/docs/topics/pages.md#inline-models

Details

The documentation states:

Each inline model requires the following:
It must inherit from {class}wagtail.models.Orderable

Working on this

If this is not really needed, I can make a pull request to state that inheriting from Orderable is optional.