update readthedocs.yml

.readthedocs.yml

@@ -1,27 +1,14 @@
-# Read the Docs configuration file
-# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
-
-# Required
 version: 2
 
-# Build documentation in the docs/ directory with Sphinx
-sphinx:
-  configuration: docs/conf.py
-
-# Build documentation with MkDocs
-#mkdocs:
-#  configuration: mkdocs.yml
-
-# Optionally build your docs in additional formats such as PDF
-formats:
-  - pdf
-
 build:
-  os: ubuntu-22.04
+  os: "ubuntu-20.04"
   tools:
-    python: "3.11"
+    python: "mambaforge-22.9"
+
+conda:
+  environment: docs/docs_env.yml
 
 python:
   install:
-    - requirements: docs/requirements.txt
-    - {path: ., method: pip}
+    - method: pip
+      path: .