[ImgBot] Optimize images

*Total -- 33.88kb -> 22.00kb (35.07%)

/public/index.png -- 25.01kb -> 15.79kb (36.85%)
/public/icons/text.gif -- 0.22kb -> 0.14kb (35.81%)
/public/icons/link.gif -- 0.24kb -> 0.16kb (32.93%)
/public/icons/FreeInternetExplorerBadge.gif -- 8.41kb -> 5.90kb (29.82%)

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

Author: ImgBotApp