➕ add: markdown-it for posterity

It should already be included from Astro, but it doesn't hurt to be more
explicit!

Author: FireIsGood

package.json

@@ -49,6 +49,7 @@
     },
     "devDependencies": {
         "@tailwindcss/typography": "^0.5.10",
+        "markdown-it": "^14.1.0",
         "mdast-util-toc": "^7.0.0",
         "prettier": "^3.2.5",
         "prettier-plugin-astro": "^0.13.0",