updated to conform to readthedocs new requirements

readthedocs.yml

@@ -1,9 +1,22 @@
 # .readthedocs.yml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
 
+# Required
+version: 2
+
+# Set the version of Python and other tools you might need
 build:
-  image: latest
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
 
-python:
-  version: 3.6
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+  configuration: docs/conf.py
 
-requirements_file: requirements_rtd.txt
+# We recommend specifying your dependencies to enable reproducible builds:
+# https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
+python:
+  install:
+  - requirements: requirements_rtd.txt