Coax Stylelint to check files in hidden folders

Stylelint ignores hidden folders by default, so we need to pass --globby-options '{"dot":true}' to ensure that CSS files in `.github` workflow folders are checked.

For background, see:
- stylelint/stylelint#6109
- stylelint/stylelint#6437 (comment)

package.json

@@ -20,7 +20,7 @@
     "prepare": "husky install",
     "prettier": "prettier --write \"**/*.{css,dita*,json,md,xml,xsl,yml}\"",
     "prettier-check": "prettier --check \"**/*.{css,dita*,json,md,xml,xsl,yml}\"",
-    "stylelint": "stylelint \"**/*.css\"",
+    "stylelint": "stylelint \"**/*.css\" --globby-options '{\"dot\":true}'",
     "test": "prettier --list-different \"**/*.{css,dita*,json,md,xml,xsl,yml}\""
   },
   "lint-staged": {