[ImgBot] Optimize images

*Total -- 1,485.51kb -> 1,202.17kb (19.07%)

/public/assets/imgs/travel-blog.png -- 1,341.82kb -> 1,069.06kb (20.33%)
/diagram.svg -- 143.69kb -> 133.11kb (7.37%)

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

Author: ImgBotApp