added dashboard

widget/dashboard/dashboard.tsx

@@ -0,0 +1,9 @@
+import { App, Astal, Gtk, Gdk } from "astal/gtk3";
+
+export default function dashboard() {
+  return (
+    <window name="dashboard" className="Dashboard">
+      <box className="DashboardMainContent"></box>
+    </window>
+  );
+}