fix: fixed styleguide link

Author: NataliaTepluhina

src/guide/migration/introduction.md

@@ -23,7 +23,7 @@ Some of the new features to keep an eye on in Vue 3 include:
 The following consists a list of breaking changes from 2.x:
 
 - [Global Vue API is changed to use an application instance](/guide/migration/global-api.html)
-- [Global and internal APIs have been restructured to be tree-shakable](/src/guide/migration/global-api-treeshaking.html)
+- [Global and internal APIs have been restructured to be tree-shakable](/guide/migration/global-api-treeshaking.html)
 - [`model` component option and `v-bind`'s `sync` modifier are removed in favor of `v-model` arguments](/guide/migration/v-model.html)
 - [Render function API changed](/guide/migration/render-function-api.html)
 - [Functional components can only be created using a plain function](/guide/migration/functional-components.html)
@@ -58,7 +58,7 @@ The following consists a list of breaking changes from 2.x:
 
 3. If you have any tests, run them and see what still fails. If you don't have tests, just open the app in your browser and keep an eye out for warnings or errors as you navigate around.
 
-4. By now, your app should be fully migrated. If you're still hungry for more though, you can read the rest of this page - or dive in to the new and improved guide from [the beginning](index.html). Many parts will be skimmable, since you're already familiar with the core concepts.
+4. By now, your app should be fully migrated. If you're still hungry for more though, you can read the rest of this page - or dive in to the new and improved guide from [the beginning](#overview). Many parts will be skimmable, since you're already familiar with the core concepts.
 
 ### How long will it take to migrate a Vue 2.x app to 3.0?
 
@@ -68,7 +68,7 @@ It depends on a few factors:
 
 - How many times you get distracted and start playing with a cool new feature. 😉  Not judging, it also happened to us while building 3.0!
 
-- Which obsolete features you're using. Most can be upgraded with find-and-replace, but others might take a few minutes. If you're not currently following best practices according to [our styleguide](/style-guide/README.html), Vue 3.0 will also try harder to force you to. This is a good thing in the long run, but could also mean a significant (though possibly overdue) refactor.
+- Which obsolete features you're using. Most can be upgraded with find-and-replace, but others might take a few minutes. If you're not currently following best practices according to [our styleguide](/style-guide/), Vue 3.0 will also try harder to force you to. This is a good thing in the long run, but could also mean a significant (though possibly overdue) refactor.
 
 ### If I upgrade to Vue 3, will I also have to upgrade Vuex and Vue Router?