Added prompt and control widgets

- Updated iOS portion of project
- Always to default landscape

lib/prompt.dart

@@ -0,0 +1,17 @@
+import 'package:flutter/material.dart';
+
+class Prompt extends StatelessWidget {
+  Prompt({@required this.targetValue});
+  final int? targetValue;
+
+  @override
+  Widget build(BuildContext context) {
+    // TODO: implement build
+    return Column(
+      children: <Widget>[
+        Text("PUT THE BULLSEYE AS CLOSE YOU CAN TO"),
+        Text("$targetValue")
+      ],
+    );
+  }
+}