Translate to Spanish: vaadin-vxx-simple example

This particular example emphasizes about using the latest vaadin release available, that currently are alpha: `14.2.0.alpha6` and stable versions: `14.1.18` and `15.0.0`

But the `pom.xml` file is using `14.0.0.rc1` updated about ~9 months ago by commit 9fd13f96809

Would we update vaadin version for the examples as well at this time?

Ref: https://github.com/vaadin/platform/releases