Using a simple circle system to build a color spectrum based on the current locations of mouseX and mouseY
@ Key Params: segments -> Determine the total segments of the color spectrum. 决定色轮会被分割成多少个三角形
beginShape - endShape -> Use `rotation()` function to build the circle. 运用画布旋转的方法构造色轮
@ Interactions: Moving cursor from left to right -> Change the radius of the circle. 改变色轮半径
Moving cursor from top to bottom -> Change the number of segments. 改变色轮分割的数量