OpenGraph not supported

[pitrou]

The OpenGraph protocol allows displaying link previews on various services, such as Facebook, Zulip...

For example the Jupyter website has OpenGraph properties:

 <meta property="og:title" content="Project Jupyter" />
 <meta property="og:description" content="The Jupyter Notebook is a web-based interactive computing platform. The notebook combines live code, equations, narrative text, visualizations, interactive dashboards and other media.
">
 <meta property="og:url" content="https://jupyter.org" />
 <meta property="og:image" content="https://jupyter.org/assets/share.png" />

Example rendering in Zulip: