Add timestamp documentation for /roomevents add (#4933)

chat-plugins/room-events.js

@@ -156,7 +156,7 @@ exports.commands = {
 	},
 	roomeventshelp: [
 		`/roomevents - Displays a list of upcoming room-specific events.`,
-		`/roomevents add [event name] | [event date/time] | [event description] - Adds a room event. Requires: @ # & ~`,
+		`/roomevents add [event name] | [event date/time] | [event description] - Adds a room event. A timestamp in event date/time field like YYYY-MM-DD HH:MM±hh:mm will be displayed in user's timezone. Requires: @ # & ~`,
 		`/roomevents remove [event name] - Deletes an event. Requires: @ # & ~`,
 		`/roomevents view [event name] - Displays information about a specific event.`,
 		`/roomevents sortby [column name] | [asc/desc (optional)] - Sorts events table by column name and an optional argument to ascending or descending order. Ascending order is default`,