Add readthedocs config file

.readthedocs.yaml

@@ -0,0 +1,16 @@
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
+
+sphinx:
+  configuration: docs/conf.py
+
+python:
+  install:
+    - method: pip
+      path: .
+      extra_requirements:
+        - docs

setup.cfg

@@ -29,3 +29,7 @@ install_requires =
 
 [options.packages.find]
 where = src
+
+[options.extras_require]
+docs =
+    sphinx