Add names of lecturers to detail page for courses

app/views/courses_crawler/show_detail.html.erb

@@ -3,6 +3,12 @@
   <h2><%= @course['title']['de'] %></h2>
   <h5><%= @course['courseType'] %> <%= @course['semesterCode'] %>, <%= @course['weeklyHours'] %> SWS, <%= @course['instituteCode'] %> <%= @course['instituteName']['de'] %> </h5>
   <%= button_to 'Add to favorites', action: :add_to_fav, number: @course['courseNumber'], semester: @course['semesterCode'] %>
+  <% if @lecturers_names != nil %>
+    <h3>Vortragende</h3>
+    <% @lecturers_names.each_with_index do |name| %>
+      <p><%= name %></p>
+    <% end %>
+  <% end %>
   <% if @course['objective']['de'] != nil %>
     <h3>Inhalt</h3>
     <%= raw @course['objective']['de'] %>