[DOM-Parsing] insertAdjacentHTML is broken (#4)

It cannot use "insert" directly. That should probably be "pre-insert". And now I introduced "insert adjacent" it should probably reuse that: https://github.com/whatwg/dom/commit/8fa7ac749d1b612504184aad2c20808a1785b370.

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/DOM-Parsing/issues/4