Checkout develop branch and run hugo server.
git checkout develop
hugo server
We used excalidraw to produce our schemas: https://excalidraw.com/
Don't forget to push the original file to the repository (example : https://github.com/etf1/etf1.github.io/blob/prez-archi-mytf1/content/post/2020/architecture/presentation/images/persisted-queries.excalidraw)
Once your schema is OK you can export it as a SVG file and compress it with https://vecta.io/nano.