Easter egg (#123)

* lol zx quant

* Adding ZX option

* Improving colour selection so we don't end up with the same colour twice. Also fixing a bug with the colour conflict resolution.

* Putting it behind a konami code

* Better comments

* Adding comment

* Removing unnecessary malloc.

src/codecs/imagequant/quantizer.ts

@@ -6,11 +6,13 @@ export async function quantize(data: ImageData, opts: QuantizeOptions): Promise<
 }
 
 export interface QuantizeOptions {
+  zx: number;
   maxNumColors: number;
   dither: number;
 }
 
 export const defaultOptions: QuantizeOptions = {
+  zx: 0,
   maxNumColors: 256,
   dither: 1.0,
 };