D2
D2 is a domain-oriented language that stands for declarative diagramming.
For example, you describe what you want to depict on a diagram, it generates an image.
CD2 includes many official themes for beautiful design of your charts right out of the box.
The language also has a built-in API for programmatic editing.
In addition to being a runnable CLI tool, D2 can also be used to create diagrams from Go programs.
Documentation: