Part of #1139 This enables to use simple UML diagrams in the documentation where it makes sense. I suggest to use [plantuml](http://en.plantuml.com/). It's available [under various licenses](https://plantuml.com/de/faq#6gn09guo09ncka3pkmxn). Integration could be done like here: https://github.com/yegor256/jekyll-plantuml
Part of #1139
This enables to use simple UML diagrams in the documentation where it makes sense. I suggest
to use plantuml. It's available under various licenses.
Integration could be done like here: https://github.com/yegor256/jekyll-plantuml