Add examples

example/allocator.cpp

@@ -0,0 +1,18 @@
+//
+// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/vinniefalco/json
+//
+
+/*
+    This example implements a custom storage adaptor
+    which uses any standard C++ allocator.
+*/
+
+int
+main()
+{
+}