Add "both" as a valid direction

stechuhr_client/config.py

@@ -33,6 +33,7 @@ update_frequency = 600
 [client]
 location = "lerchenfeld/mensa"
 entrance = "haupteingang"
+# Valid directions are "in", "out", "both"
 direction = "in"
 
 # Duration for which to ignore repeated register attempt for a card (in seconds)