doc: add an index page for the learn-ocaml documentation

Author: EmileRolley

learn-ocaml.opam

@@ -58,7 +58,7 @@ depends: [
 ]
 build: [
   [make "static"]
-  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "build" "-p" name "-j" jobs "@doc"]
 ]
 install: [
   ["mkdir" "-p" "%{_:share}%"]

src/dune

@@ -0,0 +1,3 @@
+(documentation
+  (package learn-ocaml)
+  (mld_files index))

src/index.mld

@@ -0,0 +1,13 @@
+{0 The [learn-ocaml] online platform (engine)}
+
+This contains the documentation for the exposed modules used to build binaries
+forming the engine for the learn-ocaml platform, and the common files.
+
+{1 List of documented modules}
+
+Modules documentation could be found here:
+
+{ul
+	{li {{: Test_lib/index.html} [Test_lib]}}
+	{li {{: Learnocaml_report/index.html} [Learnocaml_report]}}
+}