Add ja-JP.yml

[manabu-nakamura]

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (refactoring and improving code)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Description

This is the first version of ja-JP.yml.

'01 / 23' is preferred over '23 / 01,' '23 Jan,' or 'Jan 23' in Japan.
But, it is difficult because the date is hard coded.
Workaround: Copy _layouts/archives.html into your repository's _layouts and change the hard coded date (line 26-29):

<span class="date day" data-ts="{{ ts }}" data-df="DD">{{ post.date | date: '%d' }}</span>
<span class="date month small text-muted ms-1" data-ts="{{ ts }}" data-df="{{ df_dayjs_m }}">
  {{ post.date | date: df_strftime_m }}
</span>

⬇️

<span class="date day" data-ts="{{ ts }}" data-df="MM /">{{ post.date | date: '%m /' }}</span>
<span class="date month small text-muted ms-1" data-ts="{{ ts }}" data-df="DD">
  {{ post.date | date: '%d' }}
</span>

https://github.com/manabu-nakamura/chirpy-starter/blob/main/_layouts/archives.html
https://manabu-nakamura.github.io/chirpy-starter/archives/

https://github.com/manabu-nakamura/chirpy-starter
https://manabu-nakamura.github.io/chirpy-starter/

Additional context

#2178