Add test for "Add support for doc strings when hovering on modules".

Author: cristianoc

test/src/Hover.res

@@ -8,3 +8,17 @@ module Id = {
 //     ^hov
   type x = int
 }
+
+@ocaml.doc("This module is commented")
+module Dep: {
+  @ocaml.doc("Some doc comment")
+  let customDouble: int => int
+} = {
+  let customDouble = foo => foo * 2
+}
+
+module D = Dep
+//         ^hov
+
+let cd = D.customDouble
+//         ^hov

test/src/expected/Hover.res.txt

@@ -7,3 +7,9 @@ Hover src/Hover.res 3:5
 Hover src/Hover.res 6:7
 {"contents": "```rescript\nmodule Id = {\n  type x = int\n}\n```"}
 
+Hover src/Hover.res 19:11
+{"contents": "\nThis module is commented\n```rescript\nmodule Dep = {\n  let customDouble: int => int\n}\n```"}
+
+Hover src/Hover.res 22:11
+{"contents": "```rescript\nint => int\n```\n\nSome doc comment"}
+