doc: don't imply that we still do io.js releases
Reword the language around releases and signing keys to make it clear that new releases are all branded "Node.js."
cc @ChALkeR
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Reword the language around releases and signing keys to make it clear that new releases are all branded "Node.js."
cc @ChALkeR