[ImgBot] Optimize images

*Total -- 268.98kb -> 218.24kb (18.86%)

/images/release_pipeline_task.png -- 90.22kb -> 63.76kb (29.33%)
/ElmahIoUploadSourceMap/icon.png -- 1.15kb -> 0.86kb (25.38%)
/images/marketplace_select_organization.png -- 85.64kb -> 69.62kb (18.71%)
/images/marketplace_get_it_free.png -- 82.14kb -> 74.32kb (9.52%)
/extension-icon.png -- 9.82kb -> 9.68kb (1.45%)

Signed-off-by: ImgBotApp <ImgBotHelp@gmail.com>

Author: ImgBotApp