Update CONTRIBUTING.md (#28038)
Update CONTRIBUTING.md (#28038)

There are no content changes with this update, just a few formatting changes. The descriptions of the various tags under the "Current version, Dependency version, Unreleased Dependency version and Released Beta Dependency version" melded together and were a somewhat jumbled mess. I've bolded them and added an empty line in between the various version tag descriptions.
Azure/azure-sdk-for-java,Azure/azure-sdk-for-java,Azure/azure-sdk-for-java,Azure/azure-sdk-for-java,Azure/azure-sdk-for-java