The examples are generated by GitVersion tests, there are a number of services which will then turn the sequence diagram text into an image to use in the docs. Here are some links which could be useful
The tests are quite simple. Using the methods on the
fixture itself will record that action in the sequence
diagram. If you do not want the action recorded perform the action
directly on the repository (fixture.Repository.)
The tests for the examples should all live at DocumentationSamples.cs