fix: fixing typing issue for Broadcastable, now it's possible to have…

… a payload with an array. (#24)

src/types/main.ts

@@ -22,7 +22,13 @@ export type Duration = number | string
 /**
  * A Broadcastable is a value that can be broadcasted to other clients
  */
-export type Broadcastable = { [key: string]: Broadcastable } | string | number | boolean | null
+export type Broadcastable =
+  | { [key: string]: Broadcastable }
+  | string
+  | number
+  | boolean
+  | null
+  | Broadcastable[]
 
 export interface TransmitConfig {
   pingInterval?: Duration | false