chore(lint): correct flags for lint-fix script (#1016)

Author: JimMadge

package.json

@@ -17,7 +17,7 @@
     "link-check-offline": "lychee --config ./lychee.toml --offline --root-dir \"$(pwd)/dist/\" --remap \"all-contributors.github.io $(pwd)/dist/\" 'dist/**/*.html'",
     "link-check": "lychee --config ./lychee.toml --root-dir \"$(pwd)/dist/\" --remap \"all-contributors.github.io $(pwd)/dist/\" 'dist/**/*.html'",
     "lint": "markdownlint **/*.{md,mdx}",
-    "lint-fix": "markdownlint **/*.{md,mdx}"
+    "lint-fix": "markdownlint --fix **/*.{md,mdx}"
   },
   "dependencies": {
     "@astrojs/sitemap": "^3.5.1",