docs: fix markdown table rendering in experimental features. (zh-CN)

[dk363]

…tal features(zh-CN)

Issue for this PR

Closes #

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Fixes the broken Markdown table rendering in the "Experimental Features" section of the zh-CN docs.

There were two formatting errors causing the parser to fail:

The header separator line had too many columns (7 instead of 3).

A missing newline caused OPENCODE_EXPERIMENTAL_MARKDOWN to merge into the previous row.

Corrected the markdown syntax so the table renders properly.

How did you verify your code works?

Previewed the markdown file locally to ensure the table parses and displays correctly.

Screenshots / recordings

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Found a potential related PR:

PR #25070: "docs(web): fix zh-cn cli experimental table"

• docs(web): fix zh-cn cli experimental table #25070
• This PR also addresses experimental features table formatting in zh-CN docs, suggesting it may be related or addressing a similar issue.

Note: PR #19243 "docs: Fix formatting of experimental features table" is about experimental features table formatting but doesn't appear to be specifically zh-CN focused.