2) File->Embed->HTML gives you an HTML snippet that you embed in your page to render a vector version of the diagram. Click the viewer opens up a lightbox, zoomable vector version, that can include the diagram data in the snippet, and a edit option from the lightbox to navigate to the editor with the diagram loaded.
3) draw.io is open source, https://github.com/jgraph/drawio, if you don't want to depend on a third-party for the viewer, clone the repo, host it as a static site (doesn't need a back-end) and reference the viewer on that site instead of www.draw.io.
Dunno why you're being downvoted. The page itself isn't loading anymore, and the link you've provided in (1) does still load, so if anyone else is unable to load the page in question, see this link (1) to see the flowchart at least.
1) Add #U to the URL then the path to the diagram to create a link that loads it directly:
https://www.draw.io/#Uhttps://jonworth.eu/downloads/29jandia...
2) File->Embed->HTML gives you an HTML snippet that you embed in your page to render a vector version of the diagram. Click the viewer opens up a lightbox, zoomable vector version, that can include the diagram data in the snippet, and a edit option from the lightbox to navigate to the editor with the diagram loaded.
3) draw.io is open source, https://github.com/jgraph/drawio, if you don't want to depend on a third-party for the viewer, clone the repo, host it as a static site (doesn't need a back-end) and reference the viewer on that site instead of www.draw.io.