Added buttons!

You can now load and save from files, which also saves your current colors and the palette as well. In addition, you can download as an image or the canvas!

this wasn’t too hard, was mostly research on file prompts and saving numpy files, so I got distracted with my work quite often and went on to do other stuff.

I’m also getting better at learning to draw on this thing, and am thinking of some things I could include in the readme guide.