Fix codabar generation

generation/codabar.go

@@ -8,7 +8,7 @@ import (
 )
 
 func generateCodabar(parameters Parameters) (barcode.Barcode, error) {
-	codabarItem, err := codabar.Encode(parameters.Content)
+	codabarItem, err := codabar.Encode("A" + parameters.Content + "B")
 	if err != nil {
 		fmt.Println("Error creating Barcode", err)
 	}