Bump astro from 4.16.14 to 4.16.18 in /docs

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 4.16.14 to 4.16.18.
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/astro@4.16.18/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@4.16.18/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/package.json

@@ -15,7 +15,7 @@
     "@fontsource/fira-mono": "^5.0.8",
     "@fontsource/fira-sans": "^5.0.17",
     "@fontsource/fira-sans-condensed": "^5.0.8",
-    "astro": "^4.16.3",
+    "astro": "^4.16.18",
     "install": "^0.13.0",
     "npm": "^10.5.2",
     "sharp": "^0.33.5",