The pngquant tool was used https://pngquant.org, and particularly, the
following command:

        /usr/bin/pngquant -f --skip-if-larger --ext .png --speed 1 image.png

Before: 47584K
After : 34924K

Added both to the graph, and to the high level overview. Explaining what
is the goal of the system and how does it connect to the other systems.

Took it from https://gitlab.com/gitlab-com/www-gitlab-com/merge_requests/3232

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