Major version link for vocabulary should point to the latest **non pre-release** version

[absoludity]

The vocabulary website at https://test.uncefact.org/vocabulary/untp/ should, I think, always refer to latest non pre-release version, not the latest version (which might be a pre-release, as is the case now).

Similarly, but more importantly, if the major version URLs such as https://test.uncefact.org/vocabulary/untp/dcc/0/ that we actually use in contexts, are currently returning the latest version (which could be a pre-release), rather than the latest non pre-release version, then we could be rendering people's credentials to be invalid json-ld (as the import may have in development changes, or for a 0.x release, backwards incompatible changes). It should also always point to the latest non pre-release version, IMO, so we don't inadvertently break things.

For patches, this is normally handled automatically by semver as, for example 0.6.1 > 0.6.1-alpha1, but for any other releases, it won't (as 0.6.0-alpha1 > 0.5.0).

[JohnOnGH]

I'm presuming that a "non pre-release" is a released version, in which yes this makes sense. There is a description of the version control approach used on the site - this ought to be handled / explained there if it isn't already.