fix add videos in playlist admin

apps/core/admin.py

@@ -51,6 +51,7 @@ class VideoAdmin(admin.ModelAdmin):
 
 
 class PlayListAdmin(admin.ModelAdmin):
+    form = forms.PlaylistForm
     list_display = ['id', 'title', 'type']
     readonly_fields = ['created', 'updated']
     list_filter = ('type', 'sort')

apps/core/forms.py

 from django.contrib.admin.widgets import FilteredSelectMultiple
 from django.forms import ModelForm
 
-from .models import Video
+from .models import Video, Playlist
 
 
 class VideoForm(ModelForm):
@@ -11,3 +11,12 @@ class VideoForm(ModelForm):
         widgets = {
             'categories': FilteredSelectMultiple('Verbose name', False),
         }
+
+
+class PlaylistForm(ModelForm):
+    class Meta:
+        model = Playlist
+        fields = '__all__'
+        widgets = {
+            'videos': FilteredSelectMultiple('Verbose name', False),
+        }