Feat: support for customizing QR Code colors and adding logos

Currently, SmartyURL generates QR Codes with a standard black and white color scheme. While this is sufficient for basic scanning purposes, it would be beneficial to provide users with more control over the appearance of QR Codes. This would allow users to customize QR Codes to match their brand or to make them more visually appealing.

Specifically, I propose implementing the following features:

• Color customization: Allow users to specify the color of the QR Code modules (the black squares and white spaces).
• Logo insertion: Allow users to insert a logo into the center of the QR Code. This would allow users to brand their QR Codes and make them more recognizable. The logo image should be transparent and should not interfere with the scannability of the QR Code.

These features would provide users with more flexibility and control over the appearance of QR Codes, making them more versatile and visually appealing.