[ImgBot] Optimize images

*Total -- 168.13kb -> 102.49kb (39.04%)

/blog/getting-started-with-mern/output3.png -- 48.01kb -> 27.36kb (43.01%)
/blog/getting-started-with-mern/output1.png -- 38.47kb -> 22.33kb (41.96%)
/blog/getting-started-with-mern/output2.png -- 73.82kb -> 45.13kb (38.86%)
/static/img/use-svg-as-background-image-particle-strokes.svg -- 7.83kb -> 7.67kb (2.14%)

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

Author: ImgBotApp