list languages enabled in config for code blocks to faq page

gulpfile.js

@@ -149,6 +149,7 @@ function custompages() {
 	return gulp.src([`${paths.pug.src}/custompages/*.pug`, `${paths.pug.src}/pages/404.pug`, `${paths.pug.src}/pages/502.pug`])
 		.pipe(gulppug({
 			locals: {
+				codeLanguages: configs.highlightOptions.languageSubset,
 				defaultTheme: configs.boardDefaults.theme,
 				defaultCodeTheme: configs.boardDefaults.codeTheme
 			}

views/custompages/faq.pug

@@ -172,7 +172,11 @@ block content
 				td
 					span.code code block
 			tr
-				td(colspan=2) The "language" of code blocks is optional. Without it, automatic language detection is used. If the language is "plain", highlighting is disabled for the code block. Not all languages are supported, a subset of popular languages is used. If the language is not in the supported list, the code block will be rendered like "plain" with no highlighting.
+				td(colspan=2)
+					| The "language" of code blocks is optional. Without it, automatic language detection is used. 
+					| If the language is "plain", highlighting is disabled for the code block. Not all languages are supported, a subset of popular languages is used. 
+					| If the language is not in the supported list, the code block will be rendered like "plain" with no highlighting.
+					| Languages supported: #{codeLanguages.join(', ')}
 	.table-container.flex-center.mv-5
 		.anchor#moderation
 		table