Mermaid — diagram text editor

Bundled the Mermaid library and fonts locally and added a window compatibility script. Save with Actions → SVG; storage lasts for the window. Sharing links, Gist and “Save diagram” rely on hosted services and were not tested.

Knut Sveidqvist. github.com/mermaid-js/mermaid-live-editor. MIT; the ELK library inside is unmodified, EPL-2.0.