Some fix for replace algo and question

[ArkadiuszMichalski]

https://dom.spec.whatwg.org/#concept-node-replace
12. If child’s parent is not null, set removedNodes to a list solely containing child and remove child from its parent with the suppress observers flag set. << first "parent" and "remove" should not be linked? Especially for "remove" because I don't know if you mean "remove algo" or direct term.

And have another question, why in step 13. we again remove child from its parent? We have it in step 12, or, if child is same as node, then removing from parent is done in step 10. via "adopt algo" (https://dom.spec.whatwg.org/#concept-node-adopt).

[nox]

@ArkadiuszMichalski @annevk Some very bad amending shenanigans happened when I did the initial patch, will fix that tonight.