Following the [example](https://nextjs.org/docs/advanced-features/custom-document), avoiding the following error:
> Identifier 'Document' has already been declared
## 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`
This commit adds a development mode warning in the console
if you try to include <link rel="stylesheet"> tags in
next/head, e.g.
```
<Head>
<link ref="stylesheet" href="..." />
</Head>
```
The warning message explains that this pattern will not
work well with Suspense/streaming and recommends using a
custom Document component instead.
## Feature
- [x] 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`
- [x] Integration tests added
- [x] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [x] Errors have helpful link attached, see `contributing.md`
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>