Japanese leaderboard md file

[AkimfromParis]

Hello @clefourrier

As agreed, you will find below only the markdown file for your final correction.
I am still waiting for the official date and hour for Professor Miyao. 🇯🇵

• Add an entry to _blog.yml.
• Add a thumbnail.
• Check you use a short title and blog path.
• Upload any additional assets (such as images) to the Documentation Images repo. This is to reduce bloat in the GitHub base repo when cloning and pulling. Try to have small images to avoid a slow or expensive user experience.
• Add metadata (such as authors) to your md file. You can also specify guest or org for the authors.
• Ensure the publication date is correct.
• Preview the content. A quick way is to paste the markdown content in https://huggingface.co/new-blog. Do not click publish, this is just a way to do an early check.

[clefourrier]

Hi Akim, updated your PR to untag my colleagues on this, since I'll do the review on Monday :)