feat: srt sync and formatting

internal/formatter/formatter.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"sub-cli/internal/format/lrc"
+	"sub-cli/internal/format/srt"
 )
 
 // Format formats a subtitle file to ensure consistent formatting
@@ -15,6 +16,8 @@ func Format(filePath string) error {
 	switch ext {
 	case "lrc":
 		return lrc.Format(filePath)
+	case "srt":
+		return srt.Format(filePath)
 	default:
 		return fmt.Errorf("unsupported format for formatting: %s", ext)
 	}