Improved japanese translation

[Catastravia]

I'm sorry if this is the wrong place. (I'm newbie)

My suggestion includes two modifications.
• Correcting the spelling discrepancies, e.g., オートプレイ to 自動再生.
• Correcting unnatural expressions to natural, e.g., ギャップ to 隙間.

messages.json

[insin]

This is the right place, thank you very much, I'll look at getting these fixes into the next version.