fix footnotes with markdownIt

eleventy.config.js

@@ -3,6 +3,8 @@ import { feedPlugin } from "@11ty/eleventy-plugin-rss";
 import pluginSyntaxHighlight from "@11ty/eleventy-plugin-syntaxhighlight";
 import pluginNavigation from "@11ty/eleventy-navigation";
 import { eleventyImageTransformPlugin } from "@11ty/eleventy-img";
+import markdownIt from "markdown-it";
+import markdownItFootnote from "markdown-it-footnote";
 
 import pluginFilters from "./_config/filters.js";
 
@@ -18,6 +20,16 @@ export default async function(eleventyConfig) {
 		}
 	});
 
+	let options = {
+		html: true,
+		breaks: true,
+		linkify: true,
+	};
+
+	let markdownLib =  markdownIt(options).use(markdownItFootnote);
+
+	eleventyConfig.setLibrary("md", markdownLib);
+
 	// Copy the contents of the `public` folder to the output folder
 	// For example, `./public/css/` ends up in `_site/css/`
 	eleventyConfig