[ImgBot] Optimize images

*Total -- 569.65kb -> 422.06kb (25.91%)

/screenshots/register.png -- 24.35kb -> 15.44kb (36.61%)
/screenshots/search.png -- 30.64kb -> 19.45kb (36.51%)
/screenshots/index.png -- 24.28kb -> 15.45kb (36.38%)
/screenshots/contact.png -- 20.07kb -> 12.93kb (35.55%)
/screenshots/about.png -- 23.14kb -> 15.02kb (35.09%)
/screenshots/admin_add_doctor.png -- 25.94kb -> 17.03kb (34.35%)
/screenshots/profile.png -- 33.91kb -> 22.78kb (32.82%)
/screenshots/doctor_profile.png -- 28.93kb -> 19.61kb (32.23%)
/screenshots/admin_profile.png -- 34.98kb -> 23.91kb (31.63%)
/screenshots/login.png -- 19.00kb -> 13.02kb (31.51%)
/screenshots/admin_manage_doctor.png -- 52.40kb -> 36.41kb (30.52%)
/screenshots/doctor_login.png -- 14.64kb -> 10.52kb (28.12%)
/screenshots/admin_login.png -- 12.70kb -> 9.44kb (25.64%)
/screenshots/appointment.png -- 121.54kb -> 94.39kb (22.34%)
/img/1.jpg -- 37.94kb -> 34.48kb (9.11%)
/img/3.jpg -- 65.20kb -> 62.18kb (4.63%)

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

Author: ImgBotApp