[ImgBot] Optimize images

*Total -- 943.66kb -> 780.64kb (17.28%)

/mirage/layers/sky.png -- 13.38kb -> 0.61kb (95.45%)
/mirage/layers/1.png -- 16.61kb -> 1.60kb (90.39%)
/mirage/layers/5.png -- 16.76kb -> 2.42kb (85.58%)
/mirage/layers/3.png -- 17.28kb -> 4.25kb (75.4%)
/mirage/layers/sun-lite.png -- 19.87kb -> 5.15kb (74.11%)
/mirage/layers/sun.png -- 18.77kb -> 5.42kb (71.13%)
/mirage/layers/7.png -- 163.60kb -> 143.12kb (12.52%)
/mirage/layers/9.png -- 130.81kb -> 115.63kb (11.6%)
/mirage/layers/4.png -- 34.14kb -> 30.36kb (11.07%)
/mirage/layers/6.png -- 97.58kb -> 87.46kb (10.37%)
/mirage/layers/12.png -- 36.48kb -> 33.16kb (9.1%)
/mirage/layers/8.png -- 156.99kb -> 143.49kb (8.6%)
/mirage/layers/2.png -- 117.87kb -> 108.14kb (8.25%)
/mirage/layers/11.png -- 53.64kb -> 51.44kb (4.11%)
/mirage/layers/10.png -- 49.88kb -> 48.39kb (2.98%)

Signed-off-by: ImgBotApp <ImgBotHelp@gmail.com>

Author: ImgBotApp