Bump metalsmith-layouts from 1.8.1 to 2.3.1

Bumps [metalsmith-layouts](https://github.com/metalsmith/metalsmith-layouts) from 1.8.1 to 2.3.1.
- [Release notes](https://github.com/metalsmith/metalsmith-layouts/releases)
- [Changelog](https://github.com/metalsmith/layouts/blob/master/CHANGELOG.md)
- [Commits](metalsmith/layouts@1.8.1...v2.3.1)

---
updated-dependencies:
- dependency-name: metalsmith-layouts
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package.json

@@ -13,7 +13,7 @@
     "metalsmith-autotoc": "^0.1.3",
     "metalsmith-collections": "^0.9.0",
     "metalsmith-ignore": "^0.1.2",
-    "metalsmith-layouts": "^1.7.0",
+    "metalsmith-layouts": "^2.3.1",
     "metalsmith-less": "^2.0.0",
     "metalsmith-markdown": "^0.2.1",
     "metalsmith-metallic": "^2.0.1"