Missing XML docs in type parameter tooltips

These tooltips have been added in https://github.com/dotnet/fsharp/pull/12933. Unless I've wired something wrong, they should include XML docs (`typeparam` is listed as a [supported tag](https://docs.microsoft.com/en-us/dotnet/fsharp/language-reference/xml-documentation#recommended-tags)).

```fsharp
/// Wrap
/// Param
type Wrap<'a> =
| Bah of 'a
```

Hovering over `'a` will just display an icon and the parameter name. Using `name="'a"` is the same.