Fixed typo (vercel#36753)

## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `yarn lint`

docs/basic-features/data-fetching/client-side.md

@@ -21,7 +21,7 @@ function Profile() {
 
   useEffect(() => {
     setLoading(true)
-    fetch('api/profile-data')
+    fetch('/api/profile-data')
       .then((res) => res.json())
       .then((data) => {
         setData(data)