[ImgBot] Optimize images (#417)

*Total -- 1,162.19kb -> 1,023.63kb (11.92%)

/assets/secure-cookie.png -- 101.05kb -> 64.08kb (36.58%)
/assets/http-strict-transport-security.png -- 102.25kb -> 66.81kb (34.66%)
/assets/service-banners.png -- 62.91kb -> 41.14kb (34.6%)
/assets/enable-ws-templates.png -- 65.75kb -> 43.56kb (33.75%)
/assets/wac-intellisense-demo.gif -- 830.23kb -> 808.04kb (2.67%)

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Co-authored-by: ImgBotApp <ImgBotHelp@gmail.com>