[ImgBot] Optimize images (#19)

*Total -- 634.22kb -> 323.57kb (48.98%)

/img/18-accumulated-local-profiles/02-tree-intuition.png -- 108.27kb -> 36.00kb (66.75%)
/img/18-accumulated-local-profiles/01-linear-intuition.png -- 292.30kb -> 133.77kb (54.24%)
/img/18-accumulated-local-profiles/08-random-forest-aparment-profiles.png -- 148.00kb -> 88.53kb (40.19%)
/img/18-accumulated-local-profiles/07-accumulated-local-profiles-interection.png -- 13.33kb -> 10.00kb (24.94%)
/img/18-accumulated-local-profiles/03-ceteris-paribus-profiles-interaction.png -- 36.27kb -> 27.30kb (24.74%)
/img/18-accumulated-local-profiles/06-local-dependence-profiles-interaction.png -- 13.80kb -> 10.45kb (24.32%)
/img/18-accumulated-local-profiles/05-defining-groups.png -- 12.49kb -> 9.57kb (23.42%)
/img/18-accumulated-local-profiles/04-partial-dependence-profiles-interaction.png -- 9.76kb -> 7.96kb (18.41%)

Signed-off-by: ImgBotApp <[email protected]>
Co-authored-by: ImgBotApp <[email protected]>

Author: imgbot[bot]