Port and re-write icon code.

src/lib/PaintCounter.tsx

@@ -0,0 +1,12 @@
+import { useState } from "preact/hooks";
+
+const counts: { [key: string]: number } = {};
+
+export default function PaintCounter() {
+    const [uniqueId] = useState('' + Math.random());
+    const count = counts[uniqueId] ?? 0;
+    counts[uniqueId] = count + 1;
+    return (
+        <span>Painted {count + 1} time(s).</span>
+    )
+}