added matchmaker

src/matcmaker.ts

@@ -0,0 +1,21 @@
+
+// todo :  use queue
+export class MatchMaker {
+    private waitingUserKey : string | undefined
+
+    public onPlayersPaired!: (userKey1: string, userKey2: string) => void
+
+    public find(userKey : string) : void{
+        if(this.waitingUserKey){
+            const user1 = this.waitingUserKey as string
+            this.waitingUserKey = undefined
+            this.fireOnPlayerPaired(user1, userKey)
+        }else{
+            this.waitingUserKey = userKey
+        }
+    }
+
+    private fireOnPlayerPaired(userKey1 : string, userKey2 : string) : void {
+        this.onPlayersPaired!!(userKey1, userKey2)
+    }
+}