[ImgBot] Optimize images

*Total -- 694.15kb -> 420.99kb (39.35%)

/img/resources-per-provider.png -- 34.29kb -> 18.37kb (46.42%)
/img/azs-per-region.png -- 135.80kb -> 75.62kb (44.32%)
/img/resources-per-service.png -- 46.81kb -> 28.11kb (39.94%)
/img/azure-ip-addresses.png -- 477.25kb -> 298.88kb (37.37%)

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

Author: ImgBotApp