Black treats multiline strings (i.e. """text""") like parentheses, so something like
	parse("""
		stuff
	""")

gets turned into

	parse(
		"""
			stuff
	"""
	)

This happens because Black refuses to add another indentation before the closing """, which
is reasonable considering not every application will ignore whitespace.

This commit fixes multiline strings to nicely indent again, like so:

	parse(
		"""
			script
		"""
	)