Update RTD setup

.readthedocs.yaml

@@ -1,12 +1,16 @@
 version: 2
 
 build:
-  os: ubuntu-20.04
+  os: ubuntu-22.04
   tools:
-    python: "3.9"
-  commands:
-    - pip install poetry
-    - poetry install --with docs
-    - poetry run make html --directory=docs
-    - mkdir _readthedocs/
-    - mv docs/build/html _readthedocs/ 
+    python: "3.11"
+  jobs:
+    post_create_environment:
+      - pip install poetry
+    post_install:
+      # VIRTUAL_ENV needs to be set manually for now; see
+      # https://github.com/readthedocs/readthedocs.org/issues/11150 for details.
+      - VIRTUAL_ENV=$READTHEDOCS_VIRTUALENV_PATH poetry install --with docs,examples
+
+sphinx:
+  configuration: docs/source/conf.py