Best way to learn FOSRestBundle API
I could not find a single working example of this bundle. Also, I don't think their documentation is complete either: https://fosrestbundle.readthedocs.io/en/3.x/versioning.html
Can someone help?
fos/rest-bundle extends Symfony to help you build REST APIs (requires familiarity with this topic). Of course, an introduction into "what's REST" could help - there are plenty of resources on that on the internet. Do you want to provide an PR/introduction for this bundle's documentation?
Also, I don't think their documentation is complete either: https://fosrestbundle.readthedocs.io/en/3.x/versioning.html
What's your question? API versioning depends on ... many things. Even if it's necessary at all depends on your use-case.
After setting up the bundle, you may use it like described. If something's missing, please add a PR for updating docs (yes, they do need some updates, too) - or ask specific questions, please.