Merge pull request #7841 from ThomasWaldmann/offline-docs-1.2

readthedocs: also build offline docs, fixes #7835 (1.2-maint)

.readthedocs.yaml

@@ -28,3 +28,8 @@ python:
 
 sphinx:
     configuration: docs/conf.py
+
+formats:
+    - htmlzip
+    - pdf
+    - epub