Shadowed type generic in doc; Inherit doc type generic from class

[P1X3]

I think the following line that specifies doc return type should be updated as it is shadowed from Line 41.

angularfire/src/firestore/collection/collection.ts

Line 144 in e4400e0

doc<T>(path?: string): AngularFirestoreDocument<T> {

Essentially here is what is happening:
db.collection<Location>('locations').doc('someid').valueChanges(); // Returns Observable<unknown>
db.collection<Location>('locations').doc<Location>('someid').valueChanges(); // Returns Observable<Location>

Ideally, I think this would be more desirable result since type passed to collection call would pass down to doc call:
db.collection<Location>('locations').doc('someid').valueChanges(); // Returns Observable<Location>
db.collection<Location>('locations').doc<Location>('someid').valueChanges(); // Returns Observable<Location>

If I am not mistaken, updating the code to following will produce more desirable result (IMHO), and provide fallback if any projects out there had different type in collection and doc calls.

doc<T2 = T>(path?: string): AngularFirestoreDocument<T2> {
return new AngularFirestoreDocument<T2>(this.ref.doc(path), this.afs);
}

Related issues: #1254
PR that resolved the issue: #1286

P.S. Pardon formatting. I do not contribute enough, or at all, to know the proper code of conduct, but figured this issue might still be considered for a fix.

[P1X3]

Here is PR #2640 in case this is something that needs fixing.

[jamesdaniels]

Should be fixed in 6.1.0-rc.1. Thanks for your help.