Add permanent redirects for v2 urls (#1701)

Author: yyx990803

src/public/_redirects

@@ -10,4 +10,39 @@
 /v2/examples/svg.html               https://vuejs.org/examples/#svg   301
 /v2/examples/todomvc.html           https://vuejs.org/examples/#todomvc   301
 /v2/examples/tree-view.html         https://vuejs.org/examples/#tree   301
-/v2/*                               https://v2.vuejs.org/v2/:splat?redirect=true    302
+
+/v2/api/                                            /api/
+/v2/api/index.html                                  /api/
+/v2/guide/                                          /guide/introduction.html
+/v2/guide/index.html                                /guide/introduction.html
+/v2/guide/installation.html                         /guide/quick-start.html
+/v2/guide/instance.html             /guide/essentials/application.html
+/v2/guide/syntax.html               /guide/essentials/template-syntax.html
+/v2/guide/computed.html             /guide/essentials/computed.html
+/v2/guide/class-and-style.html      /guide/essentials/class-and-style.html
+/v2/guide/conditional.html          /guide/essentials/conditional.html
+/v2/guide/list.html                 /guide/essentials/list.html
+/v2/guide/events.html               /guide/essentials/event-handling.html
+/v2/guide/forms.html                /guide/essentials/forms.html
+/v2/guide/components.html           /guide/essentials/component-basics.html
+/v2/guide/components-registration.html                      /guide/components/registration.html
+/v2/guide/components-props.html                             /guide/components/props.html
+/v2/guide/components-custom-events.html                     /guide/components/events.html
+/v2/guide/components-slots.html                             /guide/components/slots.html
+/v2/guide/components-dynamic-async.html                     /guide/built-ins/keep-alive.html
+/v2/guide/transitions.html              /guide/built-ins/transition.html
+/v2/guide/transitioning-state.html      /guide/extras/animation.html
+/v2/guide/custom-directive.html         /guide/reusability/custom-directives.html
+/v2/guide/render-function.html          /guide/extras/render-function.html
+/v2/guide/plugins.html                  /guide/reusability/plugins.html
+/v2/guide/single-file-components.html   /guide/scaling-up/sfc.html
+/v2/guide/testing.html                  /guide/scaling-up/testing.html
+/v2/guide/typescript.html               /guide/typescript/overview.html
+/v2/guide/deployment.html               /guide/best-practices/production-deployment.html
+/v2/guide/routing.html                  /guide/scaling-up/routing.html
+/v2/guide/state-management.html         /guide/scaling-up/state-management.html
+/v2/guide/ssr.html                      /guide/scaling-up/ssr.html
+/v2/guide/security.html                 /guide/best-practices/security.html
+/v2/guide/reactivity.html               /guide/extras/reactivity-in-depth.html
+
+/v2/*                                   https://v2.vuejs.org/v2/:splat?redirect=true    302