Add option to use prism.js syntax highlighting, instead of highlight.js

[ftessier]

The ability to highlight syntax automatically in code frames is wonderful! It would be even better if one could select alternative highlighting libraries, such as prism.js which covers more languages. For example, I am working on a git presentation, and highlight.js does not highlight syntax for git commands.

[hakimel]

We're deeply tied into highlight.js for things like auto-animated code and line highlights/steps so we can't offer a choice of libraries. If highlight.js falls behind and there superior alternatives out there we could consider a full switch in the future though.

[t-fritsch]

on this topic, Highlight.js team launched a survey in which they ask for feedback on Highlight vs Prism here : highlightjs/highlight.js#3625

This has been cross-posted in Prism repo : PrismJS/prism#3557

Regarding adoption and weekly download, they're quite in the same range (but the trends differ) : https://npmtrends.com/highlight.js-vs-prismjs

Prism v1 is not updated since more than a year, but they're working on a v2 (last commit in june) : PrismJS/prism#3531

I remember having used prism on old reveal version but haven't been able to reproduce it with v4+

[ftessier]

Thanks for considering and for the insight, understood!