Feauture - Barcode subtitle

Feauture: Add custom title/subtitle below the Barcode.

line 3173: ctx.fillText(encoding.text, x, y); to something like ctx.fillText(options.subTitle || encoding.text, x, y);

Start at line 3173 where the barcode text is drawn with ctx.fillText(encoding.text, x, y), then inspect how rendering options are defined and passed through the library. Add support for a custom subtitle while preserving the existing encoded text by default, and verify the displayed output in the browser and Node.js use cases.

Written by the indexing model from the issue text.