fix(docs): Update typescript.mdx (#1701)

* Update typescript.mdx

Add an example about the case access to the return type

* Fixed words and the format with prettier

Fixed words and the format with prettier

docs/guides/typescript.mdx

@@ -17,7 +17,7 @@ Jotai relies heavily on type inferences and requires `strictNullChecks` to be en
 
 ### Primitive atoms are basically type inferred
 
-```js
+```ts
 const numAtom = atom(0) // primitive number atom
 const strAtom = atom('') // primitive string atom
 ```
@@ -43,8 +43,25 @@ const readWriteAtom = atom<string, number>(
 
 ### useAtom is typed based on atom types
 
-```js
+```ts
 const [num, setNum] = useAtom(primitiveNumAtom)
 const [num] = useAtom(readOnlyNumAtom)
 const [, setNum] = useAtom(writeOnlyNumAtom)
 ```
+
+### Access to the value type of an atom
+
+```ts
+import { ExtractAtomValue, useAtomValue } from 'jotai'
+import { userAtom } from 'state'
+import { useQuery } from '@tanstack/react-query'
+
+export default function WriteReview(hid) {
+  const user = useAtomValue(userAtom)
+  const res = useGetReviewQuery(user)
+}
+
+function useGetReviewQuery(user: ExtractAtomValue<typeof userAtom>) {
+  return fetch('/api/user/' + user.id + '/review')
+}
+```