fix(docs): add now-required configuration file for readthedocs.io

Link: https://docs.readthedocs.io/en/stable/config-file/v2.html
Signed-off-by: Cedric Hombourger <cedric.hombourger@siemens.com>

.readthedocs.yaml

@@ -0,0 +1,20 @@
+# ---------------------------------------------------------------------------
+# Configuration file for mtda.readthedocs.io builds
+# ---------------------------------------------------------------------------
+#
+# This software is a part of MTDA.
+# Copyright (C) 2024 Siemens Digital Industrial Software
+#
+# ---------------------------------------------------------------------------
+# SPDX-License-Identifier: MIT
+# ---------------------------------------------------------------------------
+
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.12"
+
+sphinx:
+  configuration: docs/conf.py