Noticed that some tips are left untranslated. They are placed in the engine repo:

• https://github.com/javascript-tutorial/engine/blob/master/markit/locales/recent/ja.yml
• https://github.com/javascript-tutorial/engine/blob/master/markit/locales/old/ja.yml
• https://github.com/javascript-tutorial/engine/blob/master/markit/locales/error/ja.yml