Post: doctools without configuration file deprecation announcement

Follows readthedocs/readthedocs.org#2483

doctool-without-configuration-file.rst

@@ -0,0 +1,25 @@
+.. post:: July 12, 2023
+   :tags: builders
+   :author: Manuel
+   :location: BCN
+   :category: Changelog
+
+Doctools without configuration file (`conf.py` / `mkdocs.yml`) are deprecated
+=============================================================================
+
+Historically, Read the Docs has created a ``docs/conf.py`` file for Sphinx projects
+and a ``mkdocs.yml`` file for MkDocs projects that don’t provide one, to make onboarding easier.
+This has been confusing a lot our users in different ways and
+**we will remove the auto-creation of a default Sphinx/MkDocs configuration file for projects that don’t have one on August 28th**.
+To avoid unexpected behavior or your documentation builds failing,
+you should add a configuration file to your project by this date.
+
+You can find a good example of a basic configuration file in our :doc:`example projects <readthedocs:examples>`:
+
+* Sphinx `example conf.py <https://github.com/readthedocs-examples/example-sphinx-basic/blob/main/docs/conf.py>`_
+* Mkdocs `example mkdocs.yml <https://github.com/readthedocs-examples/example-mkdocs-basic/blob/main/mkdocs.yml`_
+
+
+Please, `contact us`_ and let us know any inconvenient you may have with this change.
+
+.. _contact us: mailto:hello@readthedocs.org