Fix docs

{{cookiecutter.project_slug}}/docs/cleanup.py

+#!/usr/bin/env python3
+
+#  Copyright (C) 2023 ASTRON (Netherlands Institute for Radio Astronomy)
+#  SPDX-License-Identifier: Apache-2.0
+
+import os
+
+file_dir = os.path.dirname(os.path.realpath(__file__))
+
+clean_dir = os.path.join(file_dir, "source", "source_documentation")
+print(f"Cleaning.. {clean_dir}/*")
+
+if not os.path.exists(clean_dir):
+    exit()
+
+for file_name in os.listdir(clean_dir):
+    file = os.path.join(clean_dir, file_name)
+    
+    if file_name == "index.rst":
+        continue
+
+    print(f"Removing.. {file}")
+    os.remove(file)