Mark this repository as deprecated

[Juan de Dios Martínez Vallejo]

there are a lot of people on NS 8 trying to use this plugin because they don't know there is a new one. It would be nice to mark it as deprecated and report that the new plugin is this: https://github.com/NativeScript/firebase

[Jimmy Manninen]

I agree. At least add a link to the new repository in the description.