Add readthedocs configuration file

Starting from Nov 2023, Readthedocs build requires RTD configuration
file. RTD builds without it are failing.
Adding this configuration file fixes RTD build.

Change-Id: I3961508d2325077b2ac0fb0f18bc2e2a4dc8846e

.readthedocs.yaml

@@ -0,0 +1,30 @@
+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the OS, Python version and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
+
+# Build documentation in the "docs/" directory with Sphinx
+sphinx:
+  configuration: doc/source/conf.py
+
+# Optionally build your docs in additional formats such as PDF and ePub
+# formats:
+#    - pdf
+#    - epub
+
+# Optional but recommended, declare the Python requirements required
+# to build your documentation
+# See https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
+python:
+   install:
+   - requirements: docs-requirements.txt
+   - method: pip
+     path: .