Fix docs

Author: adamchainz

docs/conf.py

@@ -27,7 +27,7 @@
 # Insert the project root dir as the first element in the PYTHONPATH.
 # This lets us ensure that the source package is imported, and that its
 # version is used.
-sys.path.insert(0, project_root)
+sys.path.insert(0, os.path.join(project_root, 'src'))
 
 from django.conf import settings  # noqa
 settings.configure()