[ImgBot] Optimize images

*Total -- 9,476.70kb -> 9,100.43kb (3.97%)

/issue-22/svg-grabber.png -- 1.53kb -> 1.06kb (30.88%)
/issue-17/melonjs.svg -- 3.22kb -> 2.45kb (23.91%)
/issue-19/what-the-filter.png -- 80.58kb -> 69.20kb (14.12%)
/issue-17/color-review.png -- 5.71kb -> 4.94kb (13.54%)
/issue-22/cap.png -- 693.77kb -> 636.92kb (8.19%)
/issue-16/gif-16.gif -- 2,210.20kb -> 2,100.48kb (4.96%)
/issue-22/gif-22.gif -- 2,063.01kb -> 1,996.43kb (3.23%)
/issue-20/gif-20.gif -- 2,814.85kb -> 2,731.37kb (2.97%)
/issue-17/gif-17.gif -- 1,288.42kb -> 1,250.59kb (2.94%)
/issue-19/gif-19.gif -- 303.57kb -> 295.21kb (2.76%)
/issue-14/tagify.svg -- 11.85kb -> 11.78kb (0.55%)

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