Implement basic navbar

Signed-off-by: Tobias Eidelpes <tobias@eidelpes.info>

app/views/layouts/application.html.erb

@@ -7,9 +7,25 @@
 
     <%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
     <%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>
+
+    <meta content="width=device-width, initial-scale=1, maximum-scale=1" name="viewport">
   </head>
 
   <body>
+  <%= nav_bar do %>
+    <%= nav_link 'Home', root_path %>
+    <%= nav_link 'People', people_index_path %>
+    <%= nav_link 'Courses', courses_index_path %>
+    <%= nav_link 'Projects', projects_index_path %>
+    <%= nav_link 'Theses', theses_index_path %>
+    <a href="javascript:void(0);" class="icon" id="toggleMenu">
+      <%= show_svg('menu-white-24dp.svg') %>
+    </a>
+  <% end %>
+
+  <main>
     <%= yield %>
+  </main>
+
   </body>
 </html>