Fix link to yarnpkg 'redux vue' search results (#2558)

The old link was getting redirected to https://classic.yarnpkg.com/en/packages with no search term. I re ran the search and found that we now need to use the classic.yarnpkg.com subdomain to link to a results page.

Author: marktnoonan

src/v2/guide/state-management.md

@@ -12,7 +12,7 @@ Large applications can often grow in complexity, due to multiple pieces of state
 
 ### Information for React Developers
 
-If you're coming from React, you may be wondering how vuex compares to [redux](https://github.com/reactjs/redux), the most popular Flux implementation in that ecosystem. Redux is actually view-layer agnostic, so it can easily be used with Vue via [simple bindings](https://yarnpkg.com/en/packages?q=redux%20vue&p=1). Vuex is different in that it _knows_ it's in a Vue app. This allows it to better integrate with Vue, offering a more intuitive API and improved development experience.
+If you're coming from React, you may be wondering how vuex compares to [redux](https://github.com/reactjs/redux), the most popular Flux implementation in that ecosystem. Redux is actually view-layer agnostic, so it can easily be used with Vue via [simple bindings](https://classic.yarnpkg.com/en/packages?q=redux%20vue&p=1). Vuex is different in that it _knows_ it's in a Vue app. This allows it to better integrate with Vue, offering a more intuitive API and improved development experience.
 
 ## Simple State Management from Scratch