up-submit="false" & up-target="false" should be unified, or better documented

[boxxxie]

Bug description

<form> with up-target="false" is not respected, but it is where the documentation leads to.

docs https://unpoly.com/form-up-submit

Modifying attributes
All attributes for a[up-follow] may be used.

i was only able to discover that up-submit="false" should be used by reading up.form.config.noSubmitSelectors

so, it would be good if this is clearly documented, but i feel the documentation is ok and that the code should be updated to reflect the docs, in which case forms should respect up-target="false"

platform

using unpoly ver 2.4.1