fix: repair broken link in Spanish few-shot page

[JulianZJN]

Fixes #533

Corrects the malformed Chain-of-Thought link in the Spanish few-shot prompting page.

Verification:

• Confirmed the old malformed pattern is absent.
• Confirmed the corrected link appears exactly once.
• Confirmed the target URL returns HTTP 200.
• Ran pnpm install --frozen-lockfile.
• Ran pnpm build (14,790/14,790 static pages).
• Ran git diff --check.

[vercel]

@JulianZJN is attempting to deploy a commit to the DAIR-AI Team on Vercel.

A member of the Team first needs to authorize it.

[JulianZJN]

Friendly follow-up: this PR is still a one-line fix for the malformed Chain-of-Thought link in the Spanish few-shot page. The target URL returns 200, the old malformed pattern is gone, and the full static build completed successfully (14,790/14,790 pages).

The Vercel preview is only waiting for DAIR-AI team authorization; it has not reported a code or build failure. Could a maintainer take a look when convenient?