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/HTML/CustomElements/CustomElementRegistry.idl

@@ -0,0 +1,17 @@
+#import <DOM/Node.idl>
+
+// https://html.spec.whatwg.org/#customelementregistry
+[Exposed=Window]
+interface CustomElementRegistry {
+    [CEReactions] undefined define(DOMString name, CustomElementConstructor constructor, optional ElementDefinitionOptions options = {});
+    (CustomElementConstructor or undefined) get(DOMString name);
+    DOMString? getName(CustomElementConstructor constructor);
+    Promise<CustomElementConstructor> whenDefined(DOMString name);
+    [CEReactions] undefined upgrade(Node root);
+};
+
+callback CustomElementConstructor = HTMLElement ();
+
+dictionary ElementDefinitionOptions {
+    DOMString extends;
+};