improve file structure

config.go

@@ -1,7 +1,8 @@
 package dbx
 
-// DBConfig defines the expected structure for database configuration. Includes
-// tags for validation and maps to
+// DBConfig provides a template for database connection configuration compatible
+// with go-toolkit/config. If used as a field in a struct, remember to include
+// the `validate:"dive"` tag to ensure that the validator checks sub-fields.
 type DBConfig struct {
 	User        string `validate:"required"`
 	Password    string `validate:"required"`