@lovisix hi! It's a diagram and should be rendered by the mermaid.js JavaScript code. Anyway, it's not important: it's just a graphical visualization of what's described by the article (the two VMS, the Wireguard tunnel, the VXLan over it and the VXLan interfaces on the bridges)
@stefano
Ok thanks. It does not rendered because I use the FF extension no-script.