Convert .note style to .news style on main page .note style's comment says it's for a news banner. So change .note to .news so it doesn't interfere with .. note:: directives used on the main page. AFAICT, this style isn't actually used anywhere.

try:
    # Python 3+
    from time import perf_counter
except (ImportError, AttributeError):
    # Python 2.5-2.7
    from time import clock as perf_counter   # noqa: F401