Pontoon: Update Japanese (ja) localization of MDN
Pontoon: Update Japanese (ja) localization of MDN

Localization authors:
- Kohei Yoshino <kohei.yoshino@gmail.com>

safwanrahman/kuma,escattone/kuma,mozilla/kuma,yfdyh000/kuma,safwanrahman/kuma,jwhitlock/kuma,mozilla/kuma,Elchi3/kuma,jwhitlock/kuma,safwanrahman/kuma,Elchi3/kuma,yfdyh000/kuma,Elchi3/kuma,mozilla/kuma,jwhitlock/kuma,Elchi3/kuma,yfdyh000/kuma,a2sheppy/kuma,escattone/kuma,SphinxKnight/kuma,jwhitlock/kuma,yfdyh000/kuma,escattone/kuma,safwanrahman/kuma,a2sheppy/kuma,mozilla/kuma,a2sheppy/kuma,jwhitlock/kuma,SphinxKnight/kuma,mozilla/kuma,yfdyh000/kuma,a2sheppy/kuma,Elchi3/kuma,a2sheppy/kuma,safwanrahman/kuma,yfdyh000/kuma,SphinxKnight/kuma,safwanrahman/kuma,SphinxKnight/kuma,SphinxKnight/kuma,SphinxKnight/kuma