More customizable page backgrounds

[jasle]

Currently, Notable offers a set of predefined page backgrounds such as blank page, dot grid, lines, small square grid, and hexagon grid. While these presets are useful, they cannot be customized.

It would be great if users could further configure these backgrounds to better match their personal writing or drawing preferences.

Possible customization options:

• Grid size: Adjust spacing between dots, lines, squares, or hexagons
• Margin padding: Control the empty space between the grid and the outer page edges
• Finer lines or dots: Add optional subdivisions between the main grid elements (e.g., smaller dots between regular dots, secondary fine lines)

These customizations would give users significantly more control over page appearance and make Notable more versatile for different note-taking and sketching styles.

[Ethran]

It's too much hassle for too little benefits. It will require changing how native background are saved, doing something similar to AutoPdf. It has to be well-thought-out , as changing it latter will be a pain.

For now, the app supports repeating image as a background -- the idea behind it was that instead of native backgrounds user can chose their own.