Big update 1: colors, importing files, malloc-less canvas.

PixelData is replaced by BrushData, now Canvas contains raylib Image and Texture2D. When you draw, it draws right into the Image. However the image is a pointer to an array of pixel data, it segfaults when drawing outside the canvas (like when you want to fill to the border), thus I made sure nobody would do that by adding a border.

Anyway, I think the program is very closed to being an ancient painting program. After I added layers I might separate it into 2 versions: ancient and modern (or something like that idk).