Issue #2866817 by harsha012, Jo Fitzgerald, BrightBold, alexpott, joelpittet: Update stylelint rule no-empty-source to be consistent with Drupal's CSS standards

core/.stylelintrc.json

@@ -9,7 +9,6 @@
     "declaration-block-no-duplicate-properties": null,
     "function-linear-gradient-no-nonstandard-direction": null,
     "function-whitespace-after": null,
-    "no-empty-source": null,
     "no-unknown-animations": true,
     "number-leading-zero": "always",
     "plugin/no-browser-hacks": [true, {

core/themes/stark/css/layout.css

@@ -0,0 +1,8 @@
+/**
+ * @file
+ * Presentational styles for Drupal stark theme layout.
+ *
+ * It is left empty for testing purposes.
+ *
+ * @see https://www.drupal.org/project/drupal/issues/2349711
+ */