Firestore Unity SDK examples for new features should be added to docs.

[ferretnt]

[REQUIRED] Please fill in the following fields:

• Unity editor version: ALL
• Firebase Unity SDK version: AKLL
• Source you installed the SDK: ALL (.unitypackage or Unity Package Manager)
• Problematic Firebase Component: Firestore (Auth, Database, etc.)
• Other Firebase Components in use: None (Auth, Database, etc.)
• Additional SDKs you are using: None (Facebook, AdMob, etc.)
• Platform you are using the Unity editor on: All (Mac, Windows, or Linux)
• Platform you are targeting: iOS, Android, Editor (iOS, Android, and/or desktop)
• Scripting Runtime: ALL (Mono, and/or IL2CPP)

[REQUIRED] Please describe the issue here:

Firestore 16.1 Unity SDK actually includes support (that seems to work based on our testing) for lots of cool features like collection group queries, arraycontains, etc, but the Firestore SDK docs say this functionality isn't supported. It is, it just isn't documented (presumably because docs aren't yet updated.)

Steps to reproduce:

Have you been able to reproduce this issue with just the Firebase Unity quickstarts (this GitHub project)? Yes
What's the issue repro rate? 100%

Head to https://cloud.google.com/firestore/docs/query-data/queries
Switch language used for code snippets to "Unity".
Observe that many examples e.g. Array membership say

// This is not yet supported in the Unity SDK.

even though that functionality does seem to work in Unity SDK 16.1, e.g in the case of array contains using CollectionReference.WhereArrayContains()

Relevant Code:

Documentation issue only.

[patm1987]

Thanks for your report, feel free to add anything you find missing here!

[cherylEnkidu]

Adding internal tracking ticket: b/271315654

[ferretnt]

Closing due to inactivity. Actually I think this was even done?