[ImgBot] Optimize images

*Total -- 324.93kb -> 273.78kb (15.74%)

/Cryptography/morse_code/cyb_morse.png -- 73.70kb -> 59.79kb (18.87%)
/Forensics/binwalk/cchef.png -- 202.31kb -> 165.92kb (17.99%)
/Misc/qr_code/cobang_ss.png -- 48.92kb -> 48.07kb (1.74%)

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Author: ImgBotApp