Exported functions or static method that return a `ModuleWithProviders`
compatible structure need to provide information about the referenced
`NgModule` type in their return type.
This allows ngtsc to be able to understand the type of `NgModule` that is
being returned from calls to the function, without having to dig into the
internals of the compiled library.
There are two ways to provide this information:
* Add a type parameter to the `ModuleWithProviders` return type. E.g.
```
static forRoot(): ModuleWithProviders<SomeNgModule>;
```
* Convert the return type to a union that includes a literal type. E.g.
```
static forRoot(): (SomeOtherType)&{ngModule:SomeNgModule};
```
This commit updates the rendering of typings files to include this type
information on all matching functions/methods.
PR Close#27326
f2a1c66031