Product/932 docu project api

coscine/issues#932

src/Project/Controllers/DisciplineController.cs

@@ -2,22 +2,34 @@
 using Coscine.Database.ReturnObjects;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
+using System.Collections.Generic;
 using System.Linq;
 
 namespace Coscine.Api.Project.Controllers
 {
+
+    /// <summary>
+    /// This controller represents the actions which can be taken with a discipline object.
+    /// </summary>
     [Authorize]
     public class DisciplineController : Controller
     {
         private readonly DisciplineModel _disciplineModel;
 
+        /// <summary>
+        /// DisciplineController constructor specifying a DisciplineModel
+        /// </summary>
         public DisciplineController()
         {
             _disciplineModel = new DisciplineModel();
         }
 
+        /// <summary>
+        /// Returns all available disciplines
+        /// </summary>
+        /// <returns>All Disciplines</returns>
         [Route("[controller]")]
-        public IActionResult Index()
+        public ActionResult<IEnumerable<DisciplineObject>> Index()
         {
             return Json(_disciplineModel.GetAll()
                 .OrderBy(discipline => discipline.DisplayNameDe.Substring(discipline.DisplayNameDe.Length - 3))