add struct

internal/config/config.go

@@ -0,0 +1,19 @@
+package config
+
+type Config struct {
+	MongoURL               string
+	DBName                 string
+	ChatsCollectionName    string
+	WorkoutsCollectionName string
+	CaloriesCollectionName string
+}
+
+func NewConfig(mongoURl string, dbName string) *Config {
+	return &Config{
+		MongoURL:               mongoURl,
+		DBName:                 dbName,
+		ChatsCollectionName:    "chats",
+		WorkoutsCollectionName: "workouts",
+		CaloriesCollectionName: "calories",
+	}
+}