Append stream behaviour discrepancy

[mingan]

The documented behaviour of an append stream suggests that elements with duplicate IDs are replaced

turbo-site/_source/reference/streams.md

Line 22 in aa10dcf

If the template's first element has an id that is already used by a direct child inside the container targeted by dom_id, it is replaced instead of appended.

where in fact the duplicate elements are removed and the new versions are appended:

https://github.com/hotwired/turbo/blob/bea2f48103ee4578167be2400dcf72451b9c110b/src/core/streams/stream_actions.js#L9-L11

This potentially leads to elements being reordered which is not apparent from the documentation.