Platform owner quickstart guide: How to add more functionality?

Totally up to personal preference: this guide is now the most minimal version of what is needed to get it up and running. As a user, I would take a second look at this section after finishing the guide for the first time to explore more of its potential. On the first read, I would likely skip the link to the ServiceProvider section. But once done, my natural flow would be to scroll back up to this point to see how I can add more functionality to test it out, even if it is already linked further below.

This controls exactly which versions and services teams can request in Step 3. Add more entries to the `versions` list to offer additional versions. Note that this is also where additional Service Operators can be configured. For more information, take a look at the [`ServiceProvider`](/developers/serviceprovider/deploy) section.

Originally posted by @jn-av in https://github.com/openmcp-project/docs/pull/97#discussion_r3272387474

Locate the quoted quickstart section that explains the versions list and links to the ServiceProvider section. Clarify how users can add versions and services, then verify the guide makes that next step easy to find and the ServiceProvider link remains accurate.