Add readthedocs configuration (#14413)

.readthedocs.yaml

@@ -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: >-
+      3.11
+  commands:
+    - pip install --user tox
+    - python3 -m tox -e docs
+    - mkdir -p _readthedocs/html/
+    - mv docs/docsite/build/html/* _readthedocs/html/