Raised a more helpful ImportError message in manage.py template.

django/conf/project_template/manage.py-tpl

@@ -4,7 +4,12 @@ import sys
 
 if __name__ == "__main__":
     os.environ.setdefault("DJANGO_SETTINGS_MODULE", "{{ project_name }}.settings")
-
-    from django.core.management import execute_from_command_line
-
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and available "
+            "on your PATH environment variable? Did you forget to activate a "
+            "virtual environment?"
+        )
     execute_from_command_line(sys.argv)