feat: add config and credential storage

internal/apperrors/errors.go

@@ -0,0 +1,17 @@
+package apperrors
+
+import (
+	"errors"
+	"fmt"
+)
+
+func User(message string) error {
+	return errors.New(message)
+}
+
+func Wrap(message string, err error) error {
+	if err == nil {
+		return nil
+	}
+	return fmt.Errorf("%s: %w", message, err)
+}