Run cmake-init and setup flake.nix and default.nix

source/main.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+#include <string>
+
+#include "lib.hpp"
+
+auto main() -> int
+{
+  auto const lib = library {};
+  auto const message = "Hello from " + lib.name + "!";
+  std::cout << message << '\n';
+  return 0;
+}