[DOC release] Add note to embedded records mixin (#4719)
[DOC release] Add note to embedded records mixin (#4719)

As mentioned in https://github.com/emberjs/data/issues/4575, the fact that embedded records rely on their own serializer can cause some confusion when using different serializers inside an application.
davidpett/data,HeroicEric/data,arenoir/data,workmanw/data,rtablada/data,HeroicEric/data,swarmbox/data,swarmbox/data,davidpett/data,arenoir/data,davidpett/data,davidpett/data,HeroicEric/data,HeroicEric/data,rtablada/data,workmanw/data,arenoir/data,workmanw/data,arenoir/data,rtablada/data,workmanw/data,swarmbox/data,swarmbox/data,rtablada/data