fix: TypeScript schema definition link

Author: ahmadawais

docs/specification/2025-03-26/_index.md

@@ -19,7 +19,7 @@ they need.
 
 This specification defines the authoritative protocol requirements, based on the
 TypeScript schema in
-[schema.ts](https://github.com/modelcontextprotocol/specification/blob/main/schema/draft/schema.ts).
+[schema.ts](https://github.com/modelcontextprotocol/specification/blob/main/schema/2025-03-26/schema.ts).
 
 For implementation guides and examples, visit
 [modelcontextprotocol.io](https://modelcontextprotocol.io).