Fix readthedocs doc building issue

- Readthedocs building has been failing due to their change:
  readthedocs/readthedocs.org#10626
  Committing readthedocs setup similar to tutorial example:
  https://github.com/readthedocs/tutorial-template

Author: tkeskita

.readthedocs.yml

@@ -0,0 +1,15 @@
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+version: "2"
+
+build:
+  os: "ubuntu-22.04"
+  tools:
+    python: "3.10"
+
+python:
+  install:
+    - requirements: docs/requirements.txt
+
+sphinx:
+  configuration: docs/conf.py

docs/requirements.txt

@@ -0,0 +1,3 @@
+sphinx==7.1.2
+sphinx-rtd-theme==1.3.0rc1
+