Versioned documentation

[astefanutti]

To enable existing users, resp. early adopters, to have access to their version of the documentation, resp. the latest version, readily available, while promoting contributions to the documentation best-so-far, versioning should be setup to publish Camel K documentation, as for other Camel sub-projects.

[astefanutti]

So I've just checked, and it's all handled by making sure we apply the same change as in #2434 for each release we want to have documentation published:

We have no excuses not to make great documentation 😄!