def resolve_file(mgr, filename):
	"""
	Given a file manager (ExitStack), load the filename
	and set the exit stack to clean up. See
	https://importlib-resources.readthedocs.io/en/latest/migration.html#pkg-resources-resource-filename
	for more details.
	"""
	path = importlib_resources.path('pmxbot.web.templates', filename)
	return str(mgr.enter_context(path))
Given a file manager (ExitStack), load the filename
	and set the exit stack to clean up. See
	https://importlib-resources.readthedocs.io/en/latest/migration.html#pkg-resources-resource-filename
	for more details.