Add ActivityRetainedLifecycle to default bindings docs

[yschimke]

Since this can be injected, seems like it's missing from docs.

[yschimke]

Example

    @ActivityRetainedScoped
    @Provides
    fun providesCoroutineScope(
        activityRetainedLifecycle: ActivityRetainedLifecycle,
    ): CoroutineScope {
        return CoroutineScope(SupervisorJob() + Dispatchers.Default).also {
            activityRetainedLifecycle.addOnClearedListener {
                it.cancel()
            }
        }
    }