According to https://github.com/jgraph/drawio-github, there is multiple GitHub integration. One of them is SVG file with embedded PNG data. This format give us the possibility to use <img src="..." />
Here is an example :
Make sure to install "draw.io Desktop". (So, you can keep your graph offline.)
In the readme.md file, you can use .
This is not specific to GitHub. For example, it works fine for bitbucket. You could use it everywhere. You can version control the graph and reference diagrams.
Code released under the MIT license.

