feat(custom-widgets): complete Custom JSX v2 (#6390)

apps/docs/src/components/ui/collapsible.tsx

@@ -0,0 +1,15 @@
+import { Collapsible as CollapsiblePrimitive } from "@base-ui/react/collapsible";
+
+function Collapsible({ ...props }: CollapsiblePrimitive.Root.Props) {
+  return <CollapsiblePrimitive.Root data-slot="collapsible" {...props} />;
+}
+
+function CollapsibleTrigger({ ...props }: CollapsiblePrimitive.Trigger.Props) {
+  return <CollapsiblePrimitive.Trigger data-slot="collapsible-trigger" {...props} />;
+}
+
+function CollapsibleContent({ ...props }: CollapsiblePrimitive.Panel.Props) {
+  return <CollapsiblePrimitive.Panel data-slot="collapsible-content" {...props} />;
+}
+
+export { Collapsible, CollapsibleTrigger, CollapsibleContent };