[ImgBot] Optimize images

*Total -- 1,528.65kb -> 1,132.67kb (25.9%)

/public/images/screenshot2.png -- 143.33kb -> 90.81kb (36.64%)
/public/images/screenshot3.png -- 138.46kb -> 92.86kb (32.93%)
/public/images/screenshot1.png -- 123.36kb -> 83.77kb (32.09%)
/public/images/screenshot4.png -- 123.21kb -> 85.65kb (30.49%)
/public/images/screenshot5.png -- 999.88kb -> 779.20kb (22.07%)
/public/images/arrow_right.svg -- 0.21kb -> 0.20kb (6.54%)
/public/images/arrow_left.svg -- 0.21kb -> 0.20kb (6.51%)

Signed-off-by: ImgBotApp <[email protected]>

Author: ImgBotApp