Update RTD configuration file to v2

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

.readthedocs.yml

@@ -1,4 +1,11 @@
+version: 2
+build:
+  os: ubuntu-22.04
+  tools:
+    python: '3.11'
 python:
-  version: 3.7
-  pip_install: true
-requirements_file: null
+  install:
+    - method: pip
+      path: .
+      extra_requirements:
+        - docs