sort images to be readable

.gitlab-ci.yml

@@ -148,7 +148,7 @@ publish_listing:
     - echo "Built image,Base os,R/Python,shiny-server" > image-list.csv
     - cat image-list-fragments/*.csv >> image_list.csv
     - WHEN=$(LC_TIME="en_US.utf8" date +"%b %G")
-    - sed "s/%%date%%/${WHEN}/g" source/user_guide/image_list.rst >> image_list.rst
+    - sed "s/%%date%%/${WHEN}/g" source/user_guide/image_list.rst | sort >> image_list.rst
   artifacts:
     when: always
     paths: