[ImgBot] Optimize images

*Total -- 8,555.96kb -> 6,814.76kb (20.35%)

/git.png -- 78.59kb -> 52.30kb (33.45%)
/Basic Git Commands.png -- 352.06kb -> 237.37kb (32.58%)
/CSS Units Cheatsheet.png -- 209.64kb -> 142.21kb (32.17%)
/JavaScript DOM Cheatsheet.png -- 771.37kb -> 538.06kb (30.25%)
/Ultimate HTML Cheatsheet.png -- 710.44kb -> 509.03kb (28.35%)
/HTML cheatsheet (1).png -- 291.80kb -> 212.36kb (27.23%)
/CSS Combinator selectors1.png -- 191.10kb -> 145.49kb (23.87%)
/Combinator Selector.png -- 210.46kb -> 161.49kb (23.27%)
/Javascript  array method cheatsheet.png -- 876.11kb -> 693.78kb (20.81%)
/JavaScript Array Methods Cheatsheet1.png -- 875.21kb -> 693.20kb (20.8%)
/5 Ways to hide Element in CSS.png -- 338.44kb -> 279.07kb (17.54%)
/nth child selectors cheatsheet.png -- 173.69kb -> 144.62kb (16.74%)
/Flexbox Cheat Sheet.png -- 157.81kb -> 131.72kb (16.53%)
/JavaScript Arrow  function Cheatsheet.png -- 456.67kb -> 386.99kb (15.26%)
/5 Ways to define a function in JavaScript.png -- 245.55kb -> 208.77kb (14.98%)
/7 Ways to loop through an array in JavaScript.png -- 509.20kb -> 441.69kb (13.26%)
/CSS list-style-type Properties.png -- 484.87kb -> 421.50kb (13.07%)
/CSS Shorthands.png -- 1,153.15kb -> 1,005.26kb (12.82%)
/5 Ways to center a div .png -- 222.87kb -> 194.42kb (12.77%)
/Differences between var, let, and const.png -- 246.93kb -> 215.42kb (12.76%)

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