Goes through each node in the list.
[el1, el2, el3, ...]
Finds the nodeList for that node in replacements. el1's nodeList might look like
Replaces that element and any other elements in the node list with the
nodelist itself. resulting in
[ [el1, [el2]], el3, ...]
If a replacement is not found, it was improperly added, so we add it as a deepChild.
The nodeList of nodes to go over