Rework Marked custom HTML renderer to skip preprocess step

Marked Variables are getting cleared when the custom HTML renderer runs, because Marked.parse re-runs the whole pipeline, including the preprocessor.

Preprocess should only be run once globally during the pipeline, or the original results get overwritten (Marked Variables clears its global array of variables each time it is run)

shared/markdown.js

@@ -31,7 +31,12 @@ renderer.html = function (token) {
 		const openTag = html.substring(0, html.indexOf('>')+1);
 		html = html.substring(html.indexOf('>')+1);
 		html = html.substring(0, html.lastIndexOf('</div>'));
-		return `${openTag} ${Marked.parse(html)} </div>`;
+
+		// Repeat the markdown processing for content inside the div, minus the preprocessing and postprocessing hooks which should only run once globally
+		const opts = Marked.defaults;
+		const tokens = Marked.lexer(html, opts);
+		Marked.walkTokens(tokens, opts.walkTokens);
+		return `${openTag} ${Marked.parser(tokens, opts)} </div>`;
 	}
 	return html;
 };