Explicitly add .readthedocs.yaml configuration file

Closes #179.

Author: vitalk

.readthedocs.yml

@@ -0,0 +1,18 @@
+version: 2
+
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.12"
+
+sphinx:
+  configuration: docs/conf.py
+  fail_on_warning: true
+
+formats:
+  - pdf
+  - epub
+
+python:
+  install:
+    - requirements: requirements/docs.txt