Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibWeb/CSS/PropertyName.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2024, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/StringView.h>
+#include <LibWeb/CSS/PropertyID.h>
+
+namespace Web::CSS {
+
+// https://drafts.css-houdini.org/css-typed-om-1/#custom-property-name-string
+static bool is_a_custom_property_name_string(StringView string)
+{
+    // A string is a custom property name string if it starts with two dashes (U+002D HYPHEN-MINUS), like --foo.
+    return string.starts_with("--"sv);
+}
+
+}