Readme contains outdated information

[brhaka]

Clear and concise description of the problem

The README contains outdated information regarding compatibilty with Vue and vue-i18n versions.
The latest version of the packages supports Vue3, not Vue2 as stated.
The default branch is set to V1.x, so the readme from that version is brought up.

Suggested solution

Change the default branch to master or latest release branch.

Alternative

Update the README to match the one on https://www.npmjs.com/package/@intlify/vue-i18n-loader

Additional context

No response

Validations

• Read the Contributing Guidelines
• Read the README
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.