Add basically API documentation

src/websocket/index.ts

@@ -1,6 +1,6 @@
 /*
  * server component for the TimeLimit App
- * Copyright (C) 2019 Jonas Lochmann
+ * Copyright (C) 2019 - 2020 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -31,7 +31,7 @@ export const createWebsocketHandler = ({ connectedDevicesManager, database }: {
   const events = new EventEmitter()
 
   // this disables warnings for many listeners
-  // this is required because very single socket causes listeners
+  // this is required because every single socket causes listeners
   events.setMaxListeners(0)
 
   const eventTriggerImportantSyncForAll = 'triggerimportantsyncforall'