[ImgBot] Optimize images

*Total -- 440.63kb -> 366.62kb (16.8%)

/images/tradingview.png -- 281.38kb -> 227.22kb (19.25%)
/images/main.png -- 86.37kb -> 75.00kb (13.16%)
/icons/icon128.png -- 15.55kb -> 13.54kb (12.9%)
/images/login.png -- 52.21kb -> 46.20kb (11.52%)
/icons/icon48.png -- 3.94kb -> 3.51kb (10.87%)
/icons/icon16.png -- 1.18kb -> 1.14kb (2.99%)

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

Author: ImgBotApp