f:repeatableProperty documentation talks about including...

f:repeatableProperty documentation talks about including f:repeatableDeleteButton, but then fails to actually call d:invokeBody.
While you could put the delete button at the end of the nested config.jelly, this is ugly since it prevents reuse;
better to specify the delete button in the form using f:repeatableProperty.
f:repeatableHeteroProperty already inserted a delete button automatically, so its documentation was incorrect.