[ImgBot] Optimize images

*Total -- 1,003.13kb -> 628.89kb (37.31%)

/.github/images/color-selected-option.png -- 61.10kb -> 35.68kb (41.6%)
/.github/images/custom-borders.png -- 48.50kb -> 28.98kb (40.25%)
/.github/images/check-selected-option.png -- 53.50kb -> 32.12kb (39.95%)
/.github/images/purple-selected-option-light.png -- 54.50kb -> 33.06kb (39.33%)
/.github/images/demo-dark.png -- 187.07kb -> 114.79kb (38.64%)
/.github/images/demo-light.png -- 190.44kb -> 117.31kb (38.4%)
/.github/images/sizes.png -- 68.67kb -> 43.46kb (36.71%)
/.github/images/invalid-disabled.png -- 98.62kb -> 63.21kb (35.91%)
/.github/images/purple-selected-option-dark.png -- 50.22kb -> 32.24kb (35.79%)
/.github/images/variant-light.png -- 43.03kb -> 28.16kb (34.55%)
/.github/images/variant-dark.png -- 41.41kb -> 27.52kb (33.54%)
/.github/images/tag-color-palettes.png -- 54.88kb -> 37.33kb (31.99%)
/.github/images/tag-variants.png -- 51.21kb -> 35.02kb (31.62%)

Signed-off-by: ImgBotApp <[email protected]>

Author: ImgBotApp