Add explicit licence (Public Domain or CC0)

Author: AA-Turner

release_engineering/LICENCE.rst

@@ -0,0 +1,2 @@
+This files in this directory are placed in the public domain or under the
+CC0-1.0-Universal license, whichever is more permissive.

release_engineering/python-releases.toml

@@ -1,3 +1,22 @@
+# This file is placed in the public domain or under the
+# CC0-1.0-Universal licence, whichever is more permissive.
+#
+# This document contains the history of every release of the Python project,
+# and specifically the CPython intepreter. The data in this file were initially
+# compiled in 2025 by Adam Turner, with information primarily sourced from the
+# release PEPs and supplemented by the 'releases' section of www.python.org.
+#
+# The release schedules for Python 3.8 onwards are created from data in this
+# document. After editing this file, run the following command to regenerate
+# the relevant PEPs:
+#
+#    python -m release_engineering update-peps
+#
+# The PEP rendering system, via Sphinx, uses this document to regenerate the
+# 'release-cycle' JSON file, found at https://peps.python.org/release-cycle.json.
+# This JSON file is intended for public consumption. The format of this TOML
+# document is not guaranteed and may change without notice.
+
 # -- Python 1.6 --------------------------------------------------------------
 
 [metadata."1.6"]