docs: refine README header badges

[timzhong1024]

Summary

Refine the README header badges in both English and Chinese READMEs.

Why

The original header felt visually sparse, but adding too many badges quickly made it look noisy and overly engineering-heavy.

This PR keeps the header intentionally restrained and product-facing:

• Awesome for Agents explains the project flavor at a glance
• npm downloads gives a lightweight usage/activity signal
• License keeps the open-source status visible

What changed

• Added Awesome for Agents
• Added npm downloads
• Kept License
• Removed GitHub stars
• Removed npm version
• Removed Go Version
• Updated both README.md and README.zh.md

Why remove the other badges

• GitHub stars: useful as a social signal, but visually abrupt in this header and not essential
• npm version: adds package metadata, but not much value for first-time readers
• Go Version: emphasizes implementation details rather than user value, which is less helpful for a product-style CLI README

Result

The final header focuses on three signals only:

• project positioning
• lightweight activity signal
• license

This keeps the top of the README cleaner and easier to scan.

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