[Docs] add Shanghai Meetup - 2025/10

[kebe7jun]

Purpose

Add Shanghai Meetup 2025.

cc @youkaichao

Test Plan

Test Result

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Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.

[mergify]

Documentation preview: https://vllm--27545.org.readthedocs.build/en/27545/

[gemini-code-assist]

Code Review

This pull request adds a new Shanghai Meetup to the 'Latest News' section of the README.md. My review identifies a couple of areas for improvement. There is a minor typo in the new entry, and more importantly, the related documentation file docs/community/meetups.md has not been updated, leading to inconsistent information. Please address these points to ensure the documentation is accurate and consistent.

[youkaichao]

let's merge after the event summarization is available.