Added problem/solution

Author: mattpocock

src/07-types-deep-dive/53-understand-react-namespace-export.explainer.ts renamed to src/07-types-deep-dive/53-understand-react-namespace-export.problem.ts

@@ -0,0 +1,21 @@
+/**
+ * Questions to answer:
+ */
+
+// 1. What is the React namespace?
+// 1a. Why can it be accessed globally as a type?
+type Example = React.ReactNode;
+//             ^?
+
+/**
+ * 2a. Most namespaces can't be used as values. So how come
+ * we can use React as a value here?
+ *
+ * HINT - we're adding LOTS of things to React's namespace in
+ * later exercises, so make sure when you go-to-definition you
+ * go to its original definition, in @types/react/index.d.ts.
+ */
+const element = React.createElement("div");
+//              ^?
+
+export {};