add readthedocs config file

.readthedocs.yaml

@@ -0,0 +1,23 @@
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+version: 2
+
+# Set the OS, Python version and other tools you might need
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.10"
+
+# Build documentation in the "docs/" directory with Sphinx
+sphinx:
+  configuration: docs/conf.py
+
+formats:
+    - pdf
+    - epub
+
+
+python:
+   install:
+   - requirements: docs/requirements.txt