i18n(ja): Add new reference/content-loader-reference.mdx translation

[nemuvski]

Description

This PR adds a Japanese translation to reference/content-loader-reference.mdx.

The original English version: https://docs.astro.build/en/reference/content-loader-reference/ (on github)

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Tracked Files

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ja/reference/content-loader-reference.mdx	Localization added, will be marked as complete.

Warnings reference

Icon	Description
🔄️	The source for this localization has been updated since the creation of this pull request, make sure all changes in the source have been applied.

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[nemuvski]

Hi.
Could you please review this pull request?
Thank you in advance.

[dyskinmel]

I made a single comment but otherwise LGTM!

[dyskinmel]

Thank you for making a change! LGTM! :)

[nemuvski]

@dyskinmel
One of the links was incorrect, so I have fixed it. fb15793
I apologize for the repeated requests, but could you please review it again?