Make the waitlist teaser pop and translate it

The blue NOTE callout was too quiet. Replace it with a centered bold
line plus a bright orange "join the waitlist" badge (matches the site),
and add the same banner to the Spanish and Korean READMEs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.es.md

@@ -35,6 +35,11 @@
 
 ---
 
+<p align="center">
+  <strong>👀 Algo nuevo está por llegar.</strong> Aún no dirá qué.<br>
+  <a href="https://ponytail.dev/soon"><img src="https://img.shields.io/badge/JOIN%20THE%20WAITLIST-e08a4a?style=for-the-badge" alt="Únete a la lista"></a>
+</p>
+
 Lo conoces. Cola de caballo larga. Lentes ovalados. Lleva más tiempo en la empresa que el control de versiones. Le muestras cincuenta líneas; las mira, no dice nada, y las reemplaza por una.
 
 Ponytail lo pone dentro de tu agente de IA.

README.ko.md

@@ -35,6 +35,11 @@
 
 ---
 
+<p align="center">
+  <strong>👀 새로운 것이 다가오고 있습니다.</strong> 아직 무엇인지 말하지 않습니다.<br>
+  <a href="https://ponytail.dev/soon"><img src="https://img.shields.io/badge/JOIN%20THE%20WAITLIST-e08a4a?style=for-the-badge" alt="대기자 명단 신청"></a>
+</p>
+
 이런 사람, 다들 알 거다. 긴 포니테일에 타원형 안경. 버전 관리 시스템보다 회사에 오래 있었다. 코드 쉰 줄을 들이밀면 잠깐 보더니, 말없이 한 줄로 바꿔 놓는다.
 
 Ponytail은 그를 당신의 AI 에이전트 안에 앉혀 둔다.

README.md

@@ -35,9 +35,10 @@
 
 ---
 
-> [!NOTE]
-> **👀 Something new is coming.** The lazy senior dev has been building something. He won't say what yet.
-> **[Be the first to know →](https://ponytail.dev/soon)**
+<p align="center">
+  <strong>👀 Something new is coming.</strong> He won't say what yet.<br>
+  <a href="https://ponytail.dev/soon"><img src="https://img.shields.io/badge/JOIN%20THE%20WAITLIST-e08a4a?style=for-the-badge" alt="Join the waitlist"></a>
+</p>
 
 You know him. Long ponytail. Oval glasses. Has been at the company longer than the version control. You show him fifty lines; he looks at them, says nothing, and replaces them with one.