[ImgBot] Optimize images

*Total -- 749.95kb -> 506.28kb (32.49%)

/Codes on Turtle Graphics/DashedLine.png -- 6.25kb -> 3.11kb (50.3%)
/Codes on Turtle Graphics/Shapes.png -- 42.49kb -> 22.54kb (46.94%)
/Codes on Turtle Graphics/Spirograph.png -- 435.03kb -> 262.32kb (39.7%)
/LineSketch/sketch.png -- 28.30kb -> 18.02kb (36.32%)
/Codes on Turtle Graphics/Dot.png -- 49.15kb -> 31.47kb (35.97%)
/Codes on Turtle Graphics/Square.png -- 9.20kb -> 6.96kb (24.37%)
/Codes on Turtle Graphics/RandomWalk.png -- 38.81kb -> 31.08kb (19.91%)
/Codes on Turtle Graphics/RandomColorWalk.png -- 33.67kb -> 29.21kb (13.25%)
/Pomodoro_GUI/bg.png -- 107.06kb -> 101.57kb (5.13%)

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Author: ImgBotApp