Feature Request: Update gray/white checkerboard pattern size.

[zaun]

Is your feature request related to a problem? Please describe.
If looks like the gray/white checkerboard pattern editor background should be configurable. It is 16x16 pixels in size now, but having the option to configure the size would be nice. It would be useful as this pattern can be used for each spacing of object in the image.

Describe the solution you'd like
I'd like an option in the settings screen.

[unsettledgames]

That would be nice and probably easy to implement. We could also implement #37 since we're at it. Nice first issue for people who want to start contributing.

[skeddles]

I think the main thing is that it shouldn't scale when you zoom in. Some non-grid-aligned patterns would probably be better for pixel art too, pyxel edit has a nice one:

Also it should be dark colors to match the theme.