[ImgBot] Optimize images

*Total -- 4,749.65kb -> 4,266.53kb (10.17%)

/themes/reveal-hugo/images/reveal-hugo-hello-world.png -- 97.28kb -> 27.87kb (71.35%)
/themes/reveal-hugo/images/screenshot.png -- 86.97kb -> 57.03kb (34.43%)
/themes/reveal-hugo/exampleSite/content/logo-example/github-logo.png -- 85.71kb -> 63.19kb (26.28%)
/themes/reveal-hugo/images/tn.png -- 44.91kb -> 33.79kb (24.77%)
/themes/reveal-hugo/exampleSite/static/images/alex-litvin-790876-unsplash.jpg -- 3,745.35kb -> 3,420.93kb (8.66%)
/themes/reveal-hugo/exampleSite/content/plugin-example/sample1.jpg -- 316.23kb -> 300.40kb (5.01%)
/themes/reveal-hugo/exampleSite/content/plugin-example/sample2.jpg -- 182.20kb -> 176.90kb (2.91%)
/themes/reveal-hugo/exampleSite/content/plugin-example/sample3.jpg -- 173.23kb -> 169.07kb (2.4%)
/themes/reveal-hugo/static/highlight-js/brown-papersq.png -- 17.77kb -> 17.36kb (2.32%)

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

Author: ImgBotApp