Google Code-in

(Do "Make MediaWiki documentation translatable for your first time" first.)

You'll be upgrading existing English text and translations so that they are translatable with MediaWiki's Translate extension, which greatly improves translation workflow hence making coverage of translated docs vastly broader. You must not add new translations yourself, that's forbidden by the rules.

Detailed steps available at https://www.mediawiki.org/wiki/Project:Language_policy/Migration_list#Google_Code-in_task_description

By now you are an expert, so the requirement for this task is increased to 1300 units (unlike what the default description says).