Replace npms to official npm registry & fix isOfficial badge in plugin-manager

[LacazeThomas]

Hi,

First, thank you for this wonderful teminal !

I removed npms registry from the plugins-manager because of a wrong version display.
See issue

I switched to the official npm registry (docs available here).

---

I also fixed the bool isOfficial which is incorect in both registry.
Example for npms and npm registry there is no publisher.name but publisher.username.

Result :

Instead of :

[Eugeny]

Thank you so much! @all-contributors please add @LacazeThomas for code

[allcontributors]

@Eugeny

I've put up a pull request to add @LacazeThomas! 🎉