[editing-explainer] replaceText input event could span multiple Typing Nodes (#50)

In ContentEditbleTyping Explainer, Section 6.2:

>When the user indicates he wants to replace part of the contents of a CE Typing Node by means of a browser-builtin spell cehcker or alike, a `beforeInput` input with `inputType` set to `replaceText` is triggered.

Note that a spellchecker might find a typo in a word that is not fully contained in a single text node. Therefore the event target must not be a text node, but rather a Range. Safari in particular allows spell check to work even when words are partially bold. See #28.

Furthermore it's not clear from the spec whether a default behavior takes place? In any case if the target is a range then there can be no default behavior since it would result in Element changes. So I think the Explainer should clarify that there is no default behavior, it's up to the editor dev to make the change.

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/editing-explainer/issues/50