Use vue/server-renderer instead of @vue/server-renderer for SSR

[francoism90]

See: laravel/vue-starter-kit#162

#437 - friendly reminder this PR also may need to be updated to this package (if this is accepted). :)

[ig0r2]

You just removed '@' from npm install @vue/server-renderer and left npm install vue/server-renderer. This is wrong because server-renderer is now included as a dependency of the main vue package. That means no package needs to be installed, so the entire Install dependencies section is no longer needed.
Also, the import in code in Clustering section needs to be changed as well.