[ImgBot] optimizes images (#113)

*Total -- 170.16kb -> 146.40kb (13.97%)

/assets/img/swc-logo-blue.png -- 13.34kb -> 8.95kb (32.9%)
/assets/img/swc-logo-white.png -- 8.81kb -> 6.30kb (28.49%)
/assets/img/lc-icon-black.png -- 32.31kb -> 23.79kb (26.39%)
/assets/img/cwl-apple-icon-114x114.png -- 4.67kb -> 4.18kb (10.43%)
/assets/img/cwl-android-icon-144x144.png -- 6.16kb -> 5.59kb (9.33%)
/assets/img/cwl-apple-icon-144x144.png -- 6.16kb -> 5.59kb (9.33%)
/assets/img/cwl-ms-icon-144x144.png -- 6.16kb -> 5.59kb (9.33%)
/assets/img/cwl-apple-icon-120x120.png -- 4.90kb -> 4.45kb (9.22%)
/assets/img/cwl-apple-icon.png -- 7.34kb -> 6.67kb (9.11%)
/assets/img/cwl-apple-icon-precomposed.png -- 7.34kb -> 6.67kb (9.11%)
/assets/img/cwl-ms-icon-150x150.png -- 6.27kb -> 5.72kb (8.8%)
/assets/img/cwl-apple-icon-180x180.png -- 7.76kb -> 7.09kb (8.65%)
/assets/img/cwl-apple-icon-152x152.png -- 6.29kb -> 5.76kb (8.46%)
/assets/img/cwl-apple-icon-60x60.png -- 2.50kb -> 2.30kb (7.96%)
/assets/img/cwl-android-icon-192x192.png -- 6.77kb -> 6.29kb (7.14%)
/assets/img/cwl-ms-icon-70x70.png -- 2.89kb -> 2.69kb (6.73%)
/assets/img/cwl-apple-icon-72x72.png -- 2.97kb -> 2.78kb (6.54%)
/assets/img/cwl-android-icon-72x72.png -- 2.97kb -> 2.78kb (6.54%)
/assets/img/cwl-favicon-96x96.png -- 3.97kb -> 3.72kb (6.49%)
/assets/img/cwl-android-icon-96x96.png -- 3.97kb -> 3.72kb (6.49%)
/assets/img/cwl-android-icon-48x48.png -- 2.10kb -> 1.98kb (5.73%)
/assets/img/cwl-apple-icon-76x76.png -- 3.10kb -> 2.93kb (5.45%)
/assets/img/cwl-apple-icon-57x57.png -- 2.41kb -> 2.29kb (5.22%)
/assets/img/cwl-ms-icon-310x310.png -- 17.26kb -> 16.87kb (2.25%)
/assets/img/cwl-android-icon-36x36.png -- 1.71kb -> 1.71kb (0.06%)