remove notifs coming soon build checklist

Author: ericbrown99

docs/mini-apps/quickstart/build-checklist.mdx

@@ -41,7 +41,7 @@ Design for social lift: native share flows and social navigation turn single‑p
 
 <Card title="Sharing & Social Graph" icon="share" href="/mini-apps/technical-guides/sharing-and-social-graph" />
 
-## Notifications (coming soon)
+## Notifications 
 
 Re‑engage saved users with relevant, rate‑limited notifications at the right moments.