chore: redirect to new quickstart

Signed-off-by: OjusWiZard <[email protected]>

README.md

@@ -1,3 +1,13 @@
+<h1 align="center">
+<b> 🚨 WARNING: Repository is deprecated 🚨</b>
+</h1>
+
+<p align="center">
+This repository has been deprecated and will not be supported until further notice.
+<br>
+Please use <a href="https://github.com/valory-xyz/quickstart/">the new Quickstart</a>.
+</p>
+
 <h1 align="center">
 <b>Mech Quickstart</b>
 </h1>