[ImgBot] Optimize images

*Total -- 178.28kb -> 167.99kb (5.77%)

/assets/crawler.png -- 36.00kb -> 27.98kb (22.29%)
/assets/crawler-result.png -- 142.28kb -> 140.01kb (1.59%)

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

Author: ImgBotApp