Add Compile Reason With An OCaml Package Using Dune as a reason til

reason/compile-reason-with-an-ocaml-package-using-dune.md

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+# Compile Reason With An OCaml Package Using Dune
+
+In [Compile Reason To Native With
+Dune](reason/compile-reason-to-native-with-dune.md), I showed how to compile
+a basic ReasonML file as a native executable using Dune.
+
+Any non-trivial program will likely involve pulling in an OCaml dependency.
+For example, you may want to pull in [Lwt](https://github.com/ocsigen/lwt).
+Assuming this package is available, whether you've manually downloaded it
+via [opam](https://opam.ocaml.org/) or used something like
+[esy](https://github.com/esy/esy), you'll want to let Dune know that Lwt is
+an available library.
+
+```lisp
+;; dune
+(executable
+ (name hello_reason)
+ (libraries lwt lwt.unix))
+```
+
+The modules in the Lwt package will now be globally available to your
+Reason code.
+
+```reason
+let () = {
+  Lwt_main.run(
+    Lwt_io.printf("Hello, Reason!\n")
+  );
+};
+```
+
+When Dune builds your code, it will include and compile Lwt.
+
+See a [full example
+here](https://github.com/jbranchaud/esy-reasonml-lwt-example).