Update .readthedocs.yml

.readthedocs.yml

@@ -21,10 +21,11 @@ build:
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
   builder: html
+  configuration: docs/conf.py
 
 # Optionally build your docs in additional formats such as PDF and ePub
 formats: []
 
 # Install pyiron from conda
 conda:
-  environment: .ci_support/environment-docs.yml
+  environment: .ci_support/environment-docs.yml