Add global things from old app

src/components/ui/highlight-node.tsx

@@ -0,0 +1,15 @@
+'use client';
+
+import * as React from 'react';
+
+import type { PlateLeafProps } from 'platejs/react';
+
+import { PlateLeaf } from 'platejs/react';
+
+export function HighlightLeaf(props: PlateLeafProps) {
+  return (
+    <PlateLeaf {...props} as="mark" className="bg-highlight/30 text-inherit">
+      {props.children}
+    </PlateLeaf>
+  );
+}