clarify monorepo status
clarify monorepo status

PolymerLabs/uni-virtualizer,lit/lit,PolymerLabs/uni-virtualizer,Polymer/lit-html,lit/lit,PolymerLabs/uni-virtualizer,PolymerLabs/uni-virtualizer,Polymer/lit-html,lit/lit,lit/lit,Polymer/lit-html,Polymer/lit-html