Bump remark-lint-no-multiple-toplevel-headings from 3.1.2 to 4.0.0

Bumps [remark-lint-no-multiple-toplevel-headings](https://github.com/remarkjs/remark-lint) from 3.1.2 to 4.0.0.
- [Release notes](https://github.com/remarkjs/remark-lint/releases)
- [Changelog](https://github.com/remarkjs/remark-lint/blob/4.0.0/history.md)
- [Commits](https://github.com/remarkjs/remark-lint/commits/4.0.0)

---
updated-dependencies:
- dependency-name: remark-lint-no-multiple-toplevel-headings
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -65,7 +65,7 @@
     "remark-lint-no-heading-like-paragraph": "^4.0.0",
     "remark-lint-no-inline-padding": "^4.1.2",
     "remark-lint-no-literal-urls": "^4.0.0",
-    "remark-lint-no-multiple-toplevel-headings": "^3.1.2",
+    "remark-lint-no-multiple-toplevel-headings": "^4.0.0",
     "remark-lint-no-reference-like-url": "^3.1.2",
     "remark-lint-no-repeat-punctuation": "^0.1.4",
     "remark-lint-no-shell-dollars": "^4.0.0",