use periods in both comments in code sample

Author: d-w-moore

README.md

@@ -869,7 +869,7 @@ from irods.meta import iRODSBinOrStringMeta as MyMeta
 d = session.data_objects.get('/path/to/object')
 unencodable_octets = '\u1000'.encode('utf8')[:-1]
 
-# Use our custom client-metadata type to store arbitrary octet strings
+# Use our custom client-metadata type to store arbitrary octet strings.
 meta_view = d.metadata(iRODSMeta_type = MyMeta)
 meta_view.set(m1 := MyMeta('mybinary', unencodable_octets, b'\x02'))