refactor: improve comment about Ratelimit

A few people got the impression that if you send 6 messages
in a burst you'll only be able to send the next one in 60 seconds.
Hopefully this can resolve it.

src/context.rs

@@ -382,7 +382,7 @@ impl Context {
             translated_stockstrings: stockstrings,
             events,
             scheduler: SchedulerState::new(),
-            ratelimit: RwLock::new(Ratelimit::new(Duration::new(60, 0), 6.0)), // Allow to send 6 messages immediately, no more than once every 10 seconds.
+            ratelimit: RwLock::new(Ratelimit::new(Duration::new(60, 0), 6.0)), // Allow at least 1 message every 10 seconds + a burst of 6.
             quota: RwLock::new(None),
             quota_update_request: AtomicBool::new(false),
             resync_request: AtomicBool::new(false),