feat: initial commit.

islands/Counter.tsx

@@ -0,0 +1,16 @@
+import type { Signal } from "@preact/signals";
+import { Button } from "../components/Button.tsx";
+
+interface CounterProps {
+  count: Signal<number>;
+}
+
+export default function Counter(props: CounterProps) {
+  return (
+    <div class="flex gap-8 py-6">
+      <Button id="decrement" onClick={() => props.count.value -= 1}>-1</Button>
+      <p class="text-3xl tabular-nums">{props.count}</p>
+      <Button id="increment" onClick={() => props.count.value += 1}>+1</Button>
+    </div>
+  );
+}