[ImgBot] Optimize images

*Total -- 383.14kb -> 197.65kb (48.41%)

/media/demo.png -- 157.18kb -> 70.99kb (54.84%)
/media/demo-v2.png -- 201.03kb -> 102.40kb (49.06%)
/app/assets/images/board-2.svg -- 6.96kb -> 6.59kb (5.29%)
/app/assets/images/board-1.svg -- 5.51kb -> 5.33kb (3.26%)
/app/assets/images/board-3.svg -- 6.97kb -> 6.85kb (1.71%)
/app/assets/images/Group-login-eclipse.svg -- 2.75kb -> 2.74kb (0.11%)
/app/assets/images/Group-register-eclipse.svg -- 2.75kb -> 2.74kb (0.11%)

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

Author: ImgBotApp