docs (omnisite): TODO on docs

### Describe the bug

There is a TODO on the docs of the new site:
https://svelte.dev/docs/svelte/v5-migration-guide#:~:text=TODO%20LINK%20TO%20TUTORIAL

### Reproduction

clicking the link above

### Logs

_No response_

### System Info

```shell
irrelevant
```


### Severity

annoyance