English docs

**What problem does this feature solve? (这个功能解决了什么问题)** Make the component library more accessible to English-speaking people.

**Describe the solution you'd like (描述您想要的解决方案)** Provide an English version of https://chatui.io/. Currently, I can sort of work around this using Google Translate but the translations are often far from perfect.

**What does the proposed API look like? (你期望的 API 是怎样的)** N/A

Start by reviewing the current English accessibility of https://chatui.io/ and the repository's documentation or site entry points. Define the pages and content to translate, then verify that the resulting site provides a complete, accurate English version.

Written by the indexing model from the issue text.