add the thing that auto does target=blank

eleventy.config.js

@@ -1,5 +1,8 @@
-import { attrs } from "@mdit/plugin-attrs";
 import { eleventyImageTransformPlugin } from "@11ty/eleventy-img";
+
+import { attrs } from "@mdit/plugin-attrs";
+import { markdownitLinkAttributes } from 'markdown-it-link-attributes';
+
 import path from "node:path";
 
 import pluginFilters from "./_config/filters.js";
@@ -8,6 +11,18 @@ export default async function (eleventyConfig) {
 	/* Markdown HTML attribute parsing */
 	eleventyConfig.amendLibrary("md", (mdLib) => mdLib.use(attrs));
 
+	/* Markdown apply target="_blank" to all external links */
+	const milaOptions = {
+    matcher(href) {
+      return href.match(/^https?:\/\//);
+    },
+    attrs: {
+      target: "_blank",
+      rel: "external",
+    },
+  };
+	eleventyConfig.amendLibrary("md", (mdLib) => mdLib.use(markdownitLinkAttributes, milaOptions));
+
 	/* Bundles */
 	/* CSS */
 	eleventyConfig.addBundle("css", {

package-lock.json

@@ -5,14 +5,14 @@
 	"requires": true,
 	"packages": {
 		"": {
-			"name": "11ty",
 			"version": "1.0.0",
 			"license": "AGPL-3.0-only",
 			"devDependencies": {
 				"@11ty/eleventy": "^3.1.5",
 				"@11ty/eleventy-img": "^6.0.4",
 				"@mdit/plugin-attrs": "^0.25.1",
-				"luxon": "^3.7.2"
+				"luxon": "^3.7.2",
+				"markdown-it-link-attributes": "https://github.com/lee0c/markdown-it-link-attributes/tarball/main"
 			}
 		},
 		"node_modules/@11ty/dependency-tree": {
@@ -1798,6 +1798,13 @@
 				"markdown-it": "bin/markdown-it.mjs"
 			}
 		},
+		"node_modules/markdown-it-link-attributes": {
+			"version": "4.0.1",
+			"resolved": "https://github.com/lee0c/markdown-it-link-attributes/tarball/main",
+			"integrity": "sha512-AWUn7JiBi431HkZyXR2MRJxU0wQolHmG/TFCrRSq+w/q4mIzY7c3QKBF1eYEQwXx8IKLdmBVxZA37tp3S1ZkYQ==",
+			"dev": true,
+			"license": "MIT"
+		},
 		"node_modules/markdown-it/node_modules/entities": {
 			"version": "4.5.0",
 			"resolved": "https://registry.npmjs.org/entities/-/entities-4.5.0.tgz",

package.json

@@ -13,6 +13,7 @@
 		"@11ty/eleventy": "^3.1.5",
 		"@11ty/eleventy-img": "^6.0.4",
 		"@mdit/plugin-attrs": "^0.25.1",
-		"luxon": "^3.7.2"
+		"luxon": "^3.7.2",
+		"markdown-it-link-attributes": "https://github.com/lee0c/markdown-it-link-attributes/tarball/main"
 	}
 }