[editing-explainer] legal caret states (#51)

It has been requested that also caret movements are moved into intention events and not directly handled by contentEditableTyping. This makes sense.
Instead, I would like to put more emphasis on where the caret can actually go. It is currently quite annoying that there are many places where the caret cannot go or disappears and reappears. Does the following cover every place:

<li>Before or after any character in any <a>CE Typing Node</a>.</li>
                    <li>Before or after any inline element</li>
                    <li>Within any empty inline or block element or within any empty text node</li>

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/editing-explainer/issues/51