README.md incorrect ports in the sample code in vuejs/README.md

[Naala89]

Blob link: vuejs/README.md

The explanation text is correct, that the external port 8080 is mapped to the internal port 8080.

However, the sample docker-compose.yml code shows port 80 mapped to port 8080.

This would be updated to reflect the actual docker-compose.yml.

[NakanoMiku]

I'd like to fix it