Update rediscloud_subscription.md

Author: NoamSternRedis

docs/resources/rediscloud_subscription.md

@@ -136,7 +136,7 @@ The `maintenance_windows` object has these attributes:
 The `window` object has these attributes:
 
 * `start_hour` - What hour in the day (0-23) the window opens
-* `duration_in_hours` - How long the window is open
+* `duration_in_hours` - How long the window is open (4-24 hours)
 * `days` - A list of weekdays on which the window is open ('Monday', 'Tuesday' etc)
 
 ### Timeouts