christophevg/UmlCanvas ? reverse-engineered prompt

Build me a small web tool that lets me generate UML diagrams on an HTML5 canvas.

I want it to have two ways to create diagrams, one using a simple JavaScript style API for people who want to build them in code, and another using a text based syntax so I can just type the diagram description and see it drawn. Please include a basic demo page where I can open it in a browser and try it out right away, with a few example diagrams like classes and relationships.

If it makes sense, add a simple way to embed it in a wiki style page too, so someone can paste in commands and get a diagram. Keep it easy to run locally, with clear build or start instructions, and make sure the output looks clean and readable. Feel free to look up current docs online if you need to.