About incorporation of Japanese translation files

[t-hamano]

Hi! I'm a Gutenberg contributor from Japan.
Shusei, a Japanese community member, suggested that we could make use of this tool in Japan, and he has created a translation file for us.

I have built an environment and tried to incorporate the translation file, but I just couldn't get the translation to work. I may be doing something wrong, but could you please incorporate this translation file?

Here are the po and mo files for Japanese generated from the pot file:

ja-po-mo.zip

Perhaps it would be better to do so after the build process by #62 is complete.

If you have any questions, please contact me 👍