Remove outdated warning about alternateId readiness from Soy docs
@@ -323,8 +323,6 @@ attribute to restore access for all translators.
### Alternate IDs
-NOTE: This feature is not fully supported yet. Stay tuned for Soy announcement.
-
If you migrate from another message management scheme to Soy, that will likely
cause all your message IDs to change. In this case, use the `alternateId`
attribute to leverage the existing translated message. Unlike the `fallbackmsg`
