doc: clarify Nuxt 2

Author: harlan-zw

README.md

@@ -12,7 +12,7 @@
 [![Codecov][codecov-src]][codecov-href]
 [![License][license-src]][license-href]
 
-> [Google Analytics](https://analytics.google.com/analytics/web/) integration for [Nuxt](https://nuxtjs.org) using [vue-analytics](https://github.com/MatteoGabriele/vue-analytics).
+> [Google Analytics](https://analytics.google.com/analytics/web/) integration for [Nuxt 2](https://nuxt.com) using [vue-analytics](https://github.com/MatteoGabriele/vue-analytics).
 
 - [✨  Release Notes](./CHANGELOG.md)
 - [📖  Documentation](https://google-analytics.nuxtjs.org)