update readme

Former-commit-id: 440e9de66986ef7736361ce8ec3e23ce68655a56

.readthedocs.yaml

@@ -0,0 +1,19 @@
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.8"
+
+sphinx:
+  configuration: docs/source/conf.py
+
+formats:
+  - pdf
+
+python:
+  install:
+  - requirements: docs/requirements-docs.txt