dashboard: userlarga message yozish uchun api qoshildi

core/apps/dashboard/serializers/send_message.py

@@ -0,0 +1,7 @@
+# rest framework
+from rest_framework import serializers
+
+
+class SendMessageSerializer(serializers.Serializer):
+    user_ids = serializers.ListField(child=serializers.IntegerField())
+    message = serializers.CharField()