Add chinese comment at AttentionUnet

[anniehuang921]

Fixes # .

Description

A few sentences describing the changes proposed in this pull request.

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• Breaking change (fix or new feature that would cause existing functionality to change).
• New tests added to cover the changes.
• Integration tests passed locally by running ./runtests.sh -f -u --net --coverage.
• Quick tests passed locally by running ./runtests.sh --quick --unittests --disttests.
• In-line docstrings updated.
• Documentation updated, tested make html command in the docs/ folder.

[KumoLiu]

Hi @anniehuang921, Thank you for your contributions to the PR. I appreciate your efforts in providing comments.

However, I would like to suggest that we maintain English as the primary language for comments and documentation to ensure broader accessibility and understanding among all contributors. Additionally, it would be beneficial to use docstring format for comments in the code, as this promotes clarity and standardization.
Thank you for your understanding, and I look forward to collaborating further!