With the new feature to use a temp output dir, the script tag has an odd src attribute
If, on the other hand you do
The attached patch simply defaults to "out" if output-dir is not set, but only for the purposes of the rendering call default-index.
This is actually incorrect to do. If the user copies the index.html that this patch renders, then the REPL no longer works because it no longer points to the main.js.
The (more complicated) patch 2 adds logic that doesn't use a temp out dir if index.html exists.
Third patch rebaselines.