1. Write a function called makeGrayscale that takes an image as an argument and returns a grayscale version of the input image. To do so, create a copy of the input and iterate over each pixel. If the color of a pixel is (r, g, b) in the input image, its color in the output must be

   (m, m, m) where m is the mean (average) of r, g, and b.

In JAVASCRIPT

Pay attention to edge cases!