learn from attune

consistent with https://docs.readthedocs.io/en/stable/config-file/v2.html

.readthedocs.yml

@@ -1,13 +1,20 @@
-requirements_file: requirements.txt
+version: 2
 
 build:
-    image: latest
+  os: ubuntu-22.04
+  tools:
+    python: "3.9"
 
 python:
-  version: 3.8
-  pip_install: true
   install:
-    - requirements: docs/requirements.txt
+    - method: pip
+      path: .
+      extra_requirements:
+        - docs
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+   configuration: docs/conf.py
 
 formats:
   - epub