image optimizations (#2)

*Total -- 10,179.46kb -> 8,582.96kb (15.68%)

/imgs/traceback.png -- 807.33kb -> 497.99kb (38.32%)
/imgs/progress.gif -- 3,310.30kb -> 2,318.08kb (29.97%)
/imgs/downloader.gif -- 2,852.89kb -> 2,574.85kb (9.75%)
/imgs/status.gif -- 587.96kb -> 576.18kb (2%)
/imgs/logo.svg -- 43.99kb -> 43.84kb (0.33%)
/imgs/spinners.gif -- 1,461.22kb -> 1,456.46kb (0.33%)
/assets/logo.svg -- 1,115.77kb -> 1,115.56kb (0.02%)

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

Co-authored-by: ImgBotApp <ImgBotHelp@gmail.com>

Author: 2 people