Add QtQuick app sample code

app/CMakeLists.txt

@@ -1,7 +1,15 @@
 set(target mainApp)
 
-add_executable(${target} main.cpp)
+qt_add_executable(${target}
+    main.cpp
+)
+
+qt_add_qml_module(${target}
+    URI app
+    QML_FILES
+        main.qml
+)
 
 target_compile_features(${target} PRIVATE cxx_std_23)
 
-# target_link_libraries(${target} PRIVATE)
+target_link_libraries(${target} PRIVATE Qt6::Quick)

app/main.cpp

@@ -1,6 +1,10 @@
-#include <print>
+#include <QtGui>
+#include <QtQml>
 
-int main() {
-    std::println("Test\n");
-    return 0;
+int main(int argc, char **argv) {
+  QGuiApplication app(argc, argv);
+  QUrl source(QStringLiteral("qrc:/qt/qml/app/main.qml"));
+  QQmlApplicationEngine engine;
+  engine.load(source);
+  return app.exec();
 }

app/main.qml

@@ -0,0 +1,21 @@
+import QtQuick
+import QtQuick.Controls
+
+ApplicationWindow {
+    width: 400
+    height: 400
+    visible: true
+
+    Button {
+        id: button
+        text: "A Special Button"
+        background: Rectangle {
+            implicitWidth: 100
+            implicitHeight: 40
+            color: button.down ? "#d6d6d6" : "#f6f6f6"
+            border.color: "#26282a"
+            border.width: 1
+            radius: 4
+        }
+    }
+}