docs: API reference for multi version preparation

[kazupon]

Summary

This PR is in preparation for the API reference for vue-i18n v12.
vue-i18n v12 will drop the legacy API. As a result, the v12 API docs will be simple.

However, the vue-i18n docs need to support v9 through previous versions.
For this reason, we plan to publish API references with URL paths like the following

• v9~v11: /api/v11/
• v12 or latest: /api/

[pkg-pr-new]

Open in Stackblitz

@intlify/core

npm i https://pkg.pr.new/@intlify/core@2059

@intlify/devtools-types

npm i https://pkg.pr.new/@intlify/devtools-types@2059

@intlify/core-base

npm i https://pkg.pr.new/@intlify/core-base@2059

petite-vue-i18n

npm i https://pkg.pr.new/petite-vue-i18n@2059

@intlify/shared

npm i https://pkg.pr.new/@intlify/shared@2059

@intlify/message-compiler

npm i https://pkg.pr.new/@intlify/message-compiler@2059

vue-i18n

npm i https://pkg.pr.new/vue-i18n@2059

@intlify/vue-i18n-core

npm i https://pkg.pr.new/@intlify/vue-i18n-core@2059

commit: 4870095

[cloudflare-workers-and-pages]

Deploying vue-i18n-next with    Cloudflare Pages

Latest commit:	4870095
Status:	✅  Deploy successful!
Preview URL:	https://923a5f12.vue-i18n-next.pages.dev
Branch Preview URL:	https://docs-relocation-api.vue-i18n-next.pages.dev

View logs