Add ability to output visualization

[jakauppila]

It would be awesome if you could save or output the visualization both in a machine format and/or a JPG/PNG/etc.

I'm thinking in terms of like how Terraform allows you to perform a 'graph' output into a DOT format to build a visualization with Graphviz.

https://www.terraform.io/docs/commands/graph.html https://www.graphviz.org/