[ImgBot] Optimize images

*Total -- 2,158.07kb -> 1,985.86kb (7.98%)

/_12/output.png -- 14.43kb -> 10.81kb (25.07%)
/_13/plot.png -- 205.22kb -> 167.72kb (18.27%)
/_12/hist.png -- 42.41kb -> 36.73kb (13.4%)
/_04/output_1.jpg -- 35.91kb -> 33.24kb (7.44%)
/_07/output_1.jpg -- 84.36kb -> 78.22kb (7.27%)
/_07/output_6.jpg -- 55.14kb -> 51.25kb (7.05%)
/_07/output_5.jpg -- 83.05kb -> 77.26kb (6.97%)
/_07/output_3.jpg -- 88.07kb -> 81.94kb (6.95%)
/_03/output.jpg -- 42.02kb -> 39.12kb (6.89%)
/_07/output_4.jpg -- 87.96kb -> 81.91kb (6.88%)
/_05/output.jpg -- 29.69kb -> 27.67kb (6.82%)
/_08/output_3.jpg -- 236.73kb -> 220.64kb (6.8%)
/_07/output_2.jpg -- 97.81kb -> 91.17kb (6.78%)
/_04/output_2.jpg -- 33.54kb -> 31.29kb (6.71%)
/_08/output_2.jpg -- 265.40kb -> 247.73kb (6.66%)
/_08/output_4.jpg -- 253.15kb -> 236.42kb (6.61%)
/_08/output_1.jpg -- 249.43kb -> 233.15kb (6.52%)
/_01/output_2.jpg -- 68.05kb -> 63.92kb (6.06%)
/_01/output_1.jpg -- 78.44kb -> 73.97kb (5.69%)
/_02/output.jpg -- 79.13kb -> 74.71kb (5.59%)
/_06/output.jpg -- 28.15kb -> 26.97kb (4.18%)

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

Author: ImgBotApp