That subtask of T127354 to dedicated to Wikimania's hackathon.
During that open session, people can discover
* how to deal with [[ https://www.mediawiki.org/wiki/Help:TemplateData | TemplateData ]]
* help their wiki to have more VE-friendly templates.
It is not necessary to have technical skills to attend that session.
After that session to introduce you to TemplateData (Quattro room, 23 June at 14:00), you will be able to continue translations during the hackathon.