add VitePress integration

[userquin]

Clear and concise description of the problem

Finally VitePress has been released with the buildEnd hook: we can now create an integration here using the code in the VitePress PR: https://github.com/vuejs/vitepress/pull/709#issuecomment-1146139835

Suggested solution

Just add a new integration for VitePress: add a factory function to create the async buildEnd hook.

I need to check the logic for this integration!.

Alternative

No response

Additional context

No response

Validations

• [X] Follow our Code of Conduct
• [X] Read the Contributing Guide.
• [X] Check that there isn't already an issue that request the same feature to avoid creating a duplicate.