[ImgBot] Optimize images

*Total -- 403.85kb -> 353.91kb (12.37%)

/man-bull.png -- 348.85kb -> 301.51kb (13.57%)
/bull and man.jpg -- 55.00kb -> 52.40kb (4.73%)

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

Author: ImgBotApp