added post to admin.py and fixed css

application/admin.py

 from django.contrib import admin
+from .models import Post
 
+admin.site.register(Post)
 # Register your models here.

application/migrations/0002_post_tags.py

+# Generated by Django 2.0.6 on 2018-07-15 12:30
+
+from django.db import migrations
+import taggit.managers
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('taggit', '0002_auto_20150616_2121'),
+        ('application', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='post',
+            name='tags',
+            field=taggit.managers.TaggableManager(help_text='A comma-separated list of tags.', through='taggit.TaggedItem', to='taggit.Tag', verbose_name='Tags'),
+        ),
+    ]

application/templates/base.html

         <meta charset="UTF-8">
         <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
         <title> {% block title %}Seitenname{% endblock %}</title>
-        <link href="{% static 'css/mysite.css' %}" rel="stylesheet">
+        <link href="{% static 'css/application.css' %}" rel="stylesheet">
         <link href="{% static 'bootstrap/css/bootstrap.css' %}" rel="stylesheet">
     </head>
 
             </div>
         </nav>
 
-        {% block content %} {% endblock %}
-
+        <div class="content container">
+            <div class="row">
+                <div class="col-md-8">
+                    {% block content %} {% endblock %}
+                </div>
+            </div>
+        </div>
         <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
         <script src="{% static 'bootstrap/js/bootstrap.bundle.js' %}"></script>
     </body>

application/views.py

     context = {'error': error}
     return render(request, 'index.html', context)
 
-
+@login_required
 def post_list(request):
     posts = Post.objects.filter(
         published_date__lte=timezone.now()).order_by('published_date')
     return render(request, 'post_list.html', {'posts': posts})
 
-
+@login_required
 def post_detail(request, pk):
     post = get_object_or_404(Post, pk=pk)
     return render(request, 'post_detail.html', {'post': post})

mysite/settings.py

     'django.contrib.sessions',
     'django.contrib.messages',
     'django.contrib.staticfiles',
-    'taggit',
     'application',
+    'taggit',
 ]
 
 MIDDLEWARE = [

mysite/urls.py

 
 
 urlpatterns = [
-    url(r'^$', TemplateView.as_view(template_name="index.html")),
     url(r'^admin/', admin.site.urls),
     url(r'^navlogin/', application.views.navlogin, name='navlogin'),
     url(r'^accounts/', include('django.contrib.auth.urls')),
+    url(r'', include('application.urls'))
 ]