Add playground demo with hot reload.

example-project/src/playground.ts

@@ -0,0 +1,37 @@
+import {
+	enableHotReload,
+	registerUpdateReconciler,
+	getReloadCount,
+	hotCallExportedFunction,
+} from "@hediet/node-reload";
+
+enableHotReload();
+registerUpdateReconciler(module);
+
+import { registerDefaultExtractors } from "@hediet/debug-visualizer-data-extraction";
+registerDefaultExtractors();
+
+if (getReloadCount(module) === 0) {
+	// set interval so that the file watcher can detect changes in other files.
+	setInterval(() => {
+		hotCallExportedFunction(module, run);
+	}, 1000);
+}
+
+export function run() {
+	new Demo().run();
+}
+
+class Demo {
+	private f = new Foo(new Foo(undefined));
+	private arr = [new Foo(this.f), this.f];
+	private set = new Set([this.arr[0], new Foo(new Foo(this.arr[1]))]);
+
+	run() {
+		debugger;
+	}
+}
+
+class Foo {
+	constructor(public readonly next: Foo | undefined) {}
+}