"Design ready" quick generator

[FiratUsta]

Right now, the quick settings only do what they advertise (ie. monochrome gives monochrome colors for the given color, complementary gives two sets of complementary monochrome palettes etc.), it could be useful to have an "auto" or "design ready" setting which is ready to be used right after generation. This setting should ensure the generated palette at least has:

• A dark background color.
• A light foreground color.
• An accent color.
• Optionally a second accent color. (This could be exposed in the advanced settings to the user as an option or picked randomly.)

This setting should also ensure that:

• The colors go well together (ie. The palette is either monochromatic, analogous etc.) (This could be exposed in the advanced settings to the user as an option or picked randomly)
• The colors contrast well with one another (The contrast between the background and foreground at least should be 4.5:1, ideally the accents should contrast with the others as well but this could be hard to ensure)
• The colors also contrast well with one another for the most common forms of color blindness.

I think it's imperative that this generator works with URL and code exports regardless of any edits done on them, but the current code/URL export logic wouldn't allow this. However we'll have a set amount of colors in this mode anyway (I'm thinking a maximum of 6) so we could very well just string the HEX values one after the other for this mode only.

I'm going to put this to 2.x milestone initially, but this can be pushed back to 3.x to be released alongside #24