fix typo (#749)

Co-authored-by: Harsh Mangalam <harshmangalam@Harshs-MacBook-Air.local>

Author: harshmangalam

src/routes/solid-start/advanced/return-responses.mdx

@@ -25,7 +25,7 @@ const hello = GET(async (name: string) => {
 });
 ```
 
-However, in the this example, since `redirect` and `reload` return `never` as their type, `getUser` can only return a value of type `Promise<User>`:
+However, in this example, since `redirect` and `reload` return `never` as their type, `getUser` can only return a value of type `Promise<User>`:
 
 ```tsx { 4, 10, 14}
 export async function getUser() {