[ImgBot] Optimize images

*Total -- 94.93kb -> 55.39kb (41.65%)

/delete-pages-pdf/img/2.png -- 8.39kb -> 3.75kb (55.31%)
/delete-pages-pdf/img/1.png -- 43.94kb -> 26.04kb (40.73%)
/delete-pages-pdf/img/3.png -- 42.60kb -> 25.60kb (39.91%)

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

Author: ImgBotApp