In a gigantic realm where we send several MB of `page_params`, it’s
slightly better to have the rest of the `<body>` available to the
browser earlier, so it can show the “Loading…” spinner and start
fetching subresources.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This sidesteps tricky escaping issues, and will make it easier to
build a strict Content-Security-Policy.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>