Ouput files without .txt suffix

src/main.go

@@ -129,7 +129,7 @@ func (rb *RouterBackup) BackupCommands(commands []string, outputDir string) erro
 		return fmt.Errorf("failed to create directory %s: %v", outputDir, err)
 	}
 
-	filename := fmt.Sprintf("%s.txt", rb.hostname)
+	filename := rb.hostname
 	filepath := filepath.Join(outputDir, filename)
 
 	// Truncate file at start