[ImgBot] Optimize images (#30)

*Total -- 4,458.43kb -> 2,379.90kb (46.62%)

/docs/docs/images/test-platform/user-authentication.png -- 375.90kb -> 159.88kb (57.47%)
/docs/docs/images/test-platform/yaml-import.png -- 314.06kb -> 156.84kb (50.06%)
/docs/docs/images/test-platform/test-suites.png -- 232.92kb -> 116.43kb (50.02%)
/docs/docs/images/test-platform/scheduled-tests.png -- 240.47kb -> 120.95kb (49.7%)
/docs/docs/images/test-platform/email-weekly.png -- 238.67kb -> 124.38kb (47.88%)
/docs/docs/images/test-platform/scheduled-test-detail.png -- 322.53kb -> 170.32kb (47.19%)
/docs/docs/images/test-platform/stats.png -- 366.52kb -> 196.28kb (46.45%)
/docs/docs/images/test-platform/test-suite-detail.png -- 341.59kb -> 183.19kb (46.37%)
/docs/docs/images/test-platform/dashboard.png -- 399.02kb -> 218.54kb (45.23%)
/docs/docs/images/test-platform/user-settings.png -- 385.10kb -> 211.78kb (45.01%)
/docs/docs/images/test-platform/test-execution-detail.png -- 423.37kb -> 237.33kb (43.94%)
/docs/docs/images/test-platform/test-execution.png -- 497.15kb -> 285.93kb (42.49%)
/docs/docs/images/test-platform/email-failure-run.png -- 259.55kb -> 155.12kb (40.24%)
/docs/docs/images/document.png -- 16.72kb -> 10.95kb (34.47%)
/docs/docs/images/kb.png -- 44.87kb -> 31.97kb (28.74%)

Signed-off-by: ImgBotApp <ImgBotHelp@gmail.com>
Co-authored-by: ImgBotApp <ImgBotHelp@gmail.com>
Co-authored-by: Xavier Portilla Edo <xavi_tb@hotmail.com>

Author: 3 people