Prism.js syntax highlighting on markdown-it

markdown-it has the highlight option. Apply syntax highlighting to fenced code blocks.

In README.md, use highlight.js as highlighting engine, but can also use Prism.

const MarkdownIt = require("markdown-it");
const Prism = require("prismjs");
require("prismjs/components/prism-javascript");

const md = new MarkdownIt({
  highlight(str, lang) {
    let hl;

    try {
      hl = Prism.highlight(str, Prism.languages[lang]);
    } catch (error) {
      console.error(error);
      hl = md.utils.escapeHtml(str);
    }

    return `<pre class="language-${lang}"><code class="language-${lang}">${hl}</code></pre>`;
  },
});

This code works on nodejs.