fix

- check CHANGELOG.md ver 0.2.1-alpha

internal/errors/errors.go

@@ -0,0 +1,10 @@
+package errors
+
+import "fmt"
+
+var (
+	ErrReservedCmd      = fmt.Errorf("command name is reserved")
+	ErrInsufficientArgs = fmt.Errorf("mandatory args are missing")
+	ErrFailedToCast     = fmt.Errorf("failed to cast spell")
+	ErrNoDBProvided     = fmt.Errorf("no db provided")
+)