mixing asciidoctor-diagram and images into a single document

asciidoctor-diagram

asciidoctor-diagram allows you to mix a diagram into your doc, but GitHub doesn't render it inline. Instead, you can do this:

----
ifdef::env-github[]
image::diagram.png[]
endif::[]
ifndef::env-github[]
["plantuml", "diagram", "png"]
-----------------------------------------------
title My Diagram

object MyObject {
	   id
	   name
}

MyObject <|-- MyObject

-----------------------------------------------
endif::[]
----

This is obviously a very contrived diagram, but this will render the generated image, if you commit it to the repo alongside your .adoc file.