Bump stylelint from 13.11.0 to 13.12.0

Bumps [stylelint](https://github.com/stylelint/stylelint) from 13.11.0 to 13.12.0.
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/stylelint/stylelint/compare/13.11.0...13.12.0)

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

package.json

@@ -3,7 +3,7 @@
     "csso-cli": "^3.0.0",
     "eslint": "^7.21.0",
     "html-minifier": "^4.0.0",
-    "stylelint": "^13.11.0",
+    "stylelint": "^13.12.0",
     "stylelint-config-standard": "^20.0.0",
     "terser": "^4.8.0"
   }