PlantUML diagram support in Markdown

Wanted to add PlantUML to the supported languages in Markdown to gain:

'''plantuml

for code fencing, with the difference that the output is not a beautified code, but a UML diagram. The PlantUML text (http://plantuml.com/PlantUML_Language_Reference_Guide.pdf) is replaced by the UML diagram's graphic.

This way we get the power of UML inside markdown documents without the cost of unmaintainable inserted graphics.

• Original issue at github
• Feature request at feedback.gitlab.com
• PlantUML site