Add last_updated field to Thoughts

thoughts/models.py

@@ -19,9 +19,11 @@ class Thought(models.Model):
     media = models.FileField(upload_to="", blank=True)  # A single image, video, or sound clip per post
     media_alt = models.TextField(blank=True)  # An optional transcription of the Thought's media
     html_content = models.TextField(blank=True) # The rendered text for this thought
+    last_updated = models.DateTimeField(default=timezone.now)
 
     def save(self):
         self.update_html_content(commit=False)
+        self.last_updated = timezone.now()
         super().save()
 
     def get_media_type(self):