[ImgBot] Optimize images

*Total -- 2,836.92kb -> 2,126.21kb (25.05%)

/public/assets/images/background.png -- 1,164.27kb -> 829.93kb (28.72%)
/public/assets/cover.png -- 714.21kb -> 533.33kb (25.33%)
/public/assets/images/hero.png -- 958.44kb -> 762.95kb (20.4%)

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

Author: ImgBotApp