Hazelcast Docker version specified in documentation outdated

[JackPGreen]

The example Docker commands refer to Hazelcast 5.3, even though newer versions are available.

It would be simpler if they used latest instead, to avoid needing to update in future - but then older documentation (e.g. this "getting started" page for 5.1) might be broken if the older client isn't compatible with latest.

So for that reason I think just updating the version is safest.