README: unlock the board at 3 total votes (was 3 per case)

Match the site change — the community leaderboard now unlocks after 3 votes
in any mix of cases, not 3 in each.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

README.en.md

@@ -48,7 +48,7 @@ Pending: Mistral Medium 3.5 · GLM-5.1 · Qwen3.7-Max (PRs welcome)
 ## Arena blind battles & community board
 
 - Each case defaults to **Arena mode**: two anonymous artifacts battle (A / B / Neither) and identities reveal only after you vote; switch to **Demo Show** to browse everything (tabs are grouped by model — a model with several harnesses can be viewed singly or side by side).
-- Casting 03 votes in each case unlocks the **community leaderboard**, ranked by Bradley-Terry scores (the LMSYS Chatbot Arena approach); "neither" counts separately as both-bad.
+- Casting 03 votes total unlocks the **community leaderboard**, ranked by Bradley-Terry scores (the LMSYS Chatbot Arena approach); "neither" counts separately as both-bad.
 - Votes stay in the browser by default; deploying `worker/` (Cloudflare Worker + D1 + Turnstile, free tier) upgrades the board to sitewide crowdsourced data — see [worker/README.md](./worker/README.md).
 
 ## Structure