feat(examples): add websocket echo server implementation

Implement a basic websocket echo server within the examples directory to
demonstrate how to utilize the minotaur framework for websocket
connections. The server subscribes to connection opened events andreplies with the received packets.

examples/internal/websocket-each-server/main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"github.com/kercylan98/minotaur/minotaur"
+	"github.com/kercylan98/minotaur/minotaur/transport"
+	"github.com/kercylan98/minotaur/minotaur/transport/network"
+	"github.com/kercylan98/minotaur/minotaur/vivid"
+)
+
+func main() {
+	minotaur.NewApplication(
+		minotaur.WithNetwork(network.WebSocket(":8080")),
+	).Launch(func(app *minotaur.Application, ctx vivid.MessageContext) {
+		switch m := ctx.GetMessage().(type) {
+		case vivid.OnBoot:
+			app.GetServer().SubscribeConnOpenedEvent(app)
+		case transport.ServerConnectionOpenedEvent:
+			m.Conn.SetPacketHandler(func(ctx vivid.MessageContext, conn transport.Conn, packet transport.ConnectionReactPacketMessage) {
+				conn.Write(packet)
+			})
+		}
+	})
+}