docs: add Japanese README

[eltociear]

Description

I created Japanese translated README.

Changes

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have performed a self-review of my own code.
• My code is commented, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• Any dependent changes have been merged and published in downstream modules.

Further Comments

[vercel]

@eltociear is attempting to deploy a commit to the Toss Team on Vercel.

A member of the Team first needs to authorize it.

[changeset-bot]

⚠️ No Changeset found

Latest commit: c80364a

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