Consider generation-time code highlighting (and diagrams)

[daveaglick]

There's really no reason this needs to be done on the client other than it's easy to set up. A module that does code highlighting in a HTML file would be a nice alternative. Note that highlight.js can work via Node (https://highlightjs.org/download/) and that I recall seeing a .NET JavaScript/Node interpreter somewhere.

May also want to consider a similar approach for Mermaid diagrams.

[daveaglick]

This was done a long time ago in the HighlightCode module using the now built-in JavaScript engine.