feat: initial Pyramid project scaffold

lib/main.dart

@@ -0,0 +1,8 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:pyramid/core/app.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  runApp(const ProviderScope(child: PyramidApp()));
+}