add OPAM link

diff --git a/how_to_get_the_programming_languages_running_on_your_computer.mdwn b/how_to_get_the_programming_languages_running_on_your_computer.mdwn
index 81468bb..3ad86cb 100644 (file)
--- a/how_to_get_the_programming_languages_running_on_your_computer.mdwn
+++ b/how_to_get_the_programming_languages_running_on_your_computer.mdwn
@@ -229,7 +229,7 @@ Sometimes we may refer to Caml or ML
 more generally; but you can assume that what we're talking about always works more
 specifically in OCaml.
 
-It's helpful if in addition to OCaml you also install the Findlib add-on and/or the OPAM "package manager."
+It's helpful if in addition to OCaml you also install the Findlib add-on and/or the [OPAM](https://opam.ocaml.org) "package manager."
 These will make it easier to install additional add-ons further down the road.
 However, if you're not able to get them working, don't worry about it much.