Stylistically this sentence is somewhat content-free (if the API is really "relatively straightforward", users can see that for themselves rather than us informing them of that fact...), and we don't want to encourage people to use undocumented methods (because we can't guarantee that the API for them will remain stable).
Generating links with `link text <./path/to/doc#anchor>`__ does not work for html.
It produces a link to `./path/to/doc#anchor` instead of `./path/to/doc.html#anchor`.
It would be tempting to add `.html` before `#` but would likely cause some more issues
when generating the documentation as pdf or epub.
References on the other hand will work regardless of the output format.
These two tests are used when checking if a new page type can be created
under a page instance, or if an existing page type can move under a page
instance.
`is_creatable` better reflects what it is used for, and stops any
confusion between Wagtail's `is_abstract` and Django's `Meta.abstract`.
`is_creatable` takes in to account `Meta.abstract` now, so developers
will no longer need to set both `is_abstract` and `Meta.abstract`.
Documentation for the new attribute has been added, as well as tests.