Update requirements in README

[Tiryoh]

What does this implement/fix?

セットアップ方法を更新します。

Does this close any currently open issues?

しません。

How has this been tested?

ドキュメントの変更のみのためなし。

Any other comments?

Checklists

• [x] I have read the CONTRIBUTING guidelines.
• [x] I have checked to ensure there aren't other open Pull Requests for the same change.