[ImgBot] Optimize images

*Total -- 10,460.85kb -> 4,435.87kb (57.6%)

/misc/thresholding_sentinel2A/chilikha_ndwi_wc_t130.png -- 917.31kb -> 270.29kb (70.53%)
/misc/thresholding_sentinel2A/okeechobee_ndwi_lmc_t194.png -- 512.85kb -> 175.21kb (65.84%)
/misc/thresholding_sentinel2A/okeechobee_ndwi_wc_t110.png -- 3,062.12kb -> 1,208.16kb (60.54%)
/misc/thresholding_sentinel2A/chilikha_ndci_t167.png -- 3,096.66kb -> 1,420.18kb (54.14%)
/misc/thresholding_sentinel2A/chilikha_ndwi_lmc_t144.png -- 2,871.93kb -> 1,362.04kb (52.57%)

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