[issue/627] Replace occurrences of links pointing to old docs (#631)

Author: Tintef

src/style-guide/README.md

@@ -81,7 +81,7 @@ export default {
 In committed code, prop definitions should always be as detailed as possible, specifying at least type(s).
 
 ::: details Detailed Explanation
-Detailed [prop definitions](https://vuejs.org/v2/guide/components.html#Prop-Validation) have two advantages:
+Detailed [prop definitions](/guide/component-props.html#prop-validation) have two advantages:
 
 - They document the API of the component, so that it's easy to see how the component is meant to be used.
 - In development, Vue will warn you if a component is ever provided incorrectly formatted props, helping you catch potential sources of error.
@@ -1617,9 +1617,9 @@ app.component('TodoItem', {
 
 **[Vuex](https://github.com/vuejs/vuex) should be preferred for global state management, instead of `this.$root` or a global event bus.**
 
-Managing state on `this.$root` and/or using a [global event bus](https://vuejs.org/v2/guide/migration.html#dispatch-and-broadcast-replaced) can be convenient for very simple cases, but it is not appropriate for most applications.
+Managing state on `this.$root` and/or using a global event bus can be convenient for very simple cases, but it is not appropriate for most applications.
 
-Vuex is the [official flux-like implementation](https://vuejs.org/v2/guide/state-management.html#Official-Flux-Like-Implementation) for Vue, and offers not only a central place to manage state, but also tools for organizing, tracking, and debugging state changes. It integrates well in the Vue ecosystem (including full [Vue DevTools](https://vuejs.org/v2/guide/installation.html#Vue-Devtools) support).
+Vuex is the [official flux-like implementation](/guide/state-management.html#official-flux-like-implementation) for Vue, and offers not only a central place to manage state, but also tools for organizing, tracking, and debugging state changes. It integrates well in the Vue ecosystem (including full [Vue DevTools](/guide/installation.html#vue-devtools) support).
 
 <div class="style-example style-example-bad">
 <h4>Bad</h4>