[ImgBot] Optimize images

*Total -- 395.43kb -> 370.01kb (6.43%)

/static/logo_code.png -- 2.82kb -> 2.22kb (21.04%)
/src/lib/cpplogo.svg -- 1.85kb -> 1.57kb (15.1%)
/src/lib/web_logo.jpg -- 96.74kb -> 90.35kb (6.6%)
/static/web_logo.jpg -- 96.74kb -> 90.35kb (6.6%)
/static/logo_preview.jpg -- 98.64kb -> 92.75kb (5.97%)
/src/lib/logo_preview.jpg -- 98.64kb -> 92.75kb (5.97%)

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

Author: ImgBotApp