docs: optimize head section of templates Reordered the head section of website/www using capo.js to improve speed. Tried to do the same for the doc/_template/layout.html. Due to a bug in sphinx, we get duplicate viewport tags. https://github.com/sphinx-doc/sphinx/issues/11699 but I think it's harmless.

# https://issues.roundup-tracker.org/issue2551278
# datetime.utcnow deprecated
try:
    from datetime import datetime, UTC

    def utcnow():
        return datetime.now(UTC)

except ImportError:
    from datetime import datetime

    def utcnow():
        return datetime.utcnow()