My general thought has been to treat text nodes as subordinate to the elements. So, if we encounter a text node in the old tree that doesn't have a parallel in the new one, we just delete it to try to get us closer to the next element vs. element comparison.

`addElementInsert` will only add an insert edit and increment the `currentIndex` if the element is new. In other words, if it's not new, the pointer in the new tree stays in the same place and only the `oldIndex` moves forward so that a comparison can be made of the same current element and the next old element.