The objective is to UI migrate from OOUI to Codex
Script: https://meta.wikimedia.org/wiki/Indic-TechCom/Tools/MassMove
Script code: https://meta.wikimedia.org/w/index.php?title=User:Indic-TechCom/Script/massMover.js
Reference guide: https://www.mediawiki.org/wiki/Codex#Using_Codex_in_userscripts
Example of the codex in user script: https://en.wikipedia.org/wiki/User:EGardner_(WMF)/codex-hello-world.js