Update docs comparison.zh-cn.md (go-gitea#21035)

- Update Chinese translation from comparison.en-us.md
<!--

Please check the following:

1. Make sure you are targeting the `main` branch, pull requests on
release branches are only allowed for bug fixes.
2. Read contributing guidelines:
https://github.com/go-gitea/gitea/blob/main/CONTRIBUTING.md
3. Describe what your pull request does and which issue you're targeting
(if any)

-->

Co-authored-by: Lunny Xiao <[email protected]>
Co-authored-by: 6543 <[email protected]>

Author: 3 people