[doc] Fix typo in WebSocketServer description (#1996)

Author: tniessen

doc/ws.md

@@ -91,7 +91,7 @@ must be provided or an error is thrown. An HTTP server is automatically created,
 started, and used if `port` is set. To use an external HTTP/S server instead,
 specify only `server` or `noServer`. In this case the HTTP/S server must be
 started manually. The "noServer" mode allows the WebSocket server to be
-completly detached from the HTTP/S server. This makes it possible, for example,
+completely detached from the HTTP/S server. This makes it possible, for example,
 to share a single HTTP/S server between multiple WebSocket servers.
 
 > **NOTE:** Use of `verifyClient` is discouraged. Rather handle client