[ImgBot] Optimize images

*Total -- 112.68kb -> 92.32kb (18.07%)

/site/images/logo.png -- 56.34kb -> 46.16kb (18.07%)
/docs/images/logo.png -- 56.34kb -> 46.16kb (18.07%)

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

Author: ImgBotApp