fix: @ is optional in bat comment (#21)

diff --git a/pkg/license/norm.go b/pkg/license/norm.go
index 1e723f3..0bc056b 100644
--- a/pkg/license/norm.go
+++ b/pkg/license/norm.go
@@ -58,8 +58,8 @@
 		regexp.MustCompile(`(?m)^\s*{-+`), // {-
 		regexp.MustCompile(`(?m)^\s*-}+`), // -}
 
-		regexp.MustCompile(`(?m)^\s*::`),    // ::
-		regexp.MustCompile(`(?mi)^\s*@REM`), // @REM
+		regexp.MustCompile(`(?m)^\s*::`),     // ::
+		regexp.MustCompile(`(?mi)^\s*@?REM`), // @REM
 	}
 
 	flattenSpace = regexp.MustCompile(`\s+`)