Need

It's nice to have ways to highlight when something comes into the library, especially newer features xref: #15920

If we can add a tag for versions, that'll let us highlight what in the gallery came in on a specific version -> specifically new features. Tagging by version number means we don't have to move a whole bunch of tags on every new version. Adding "and add tag: N.M" to the other documenting new features instructions isn't a big deal.

Proposed solution

We should use the same format as the versioning directives, version: 3.N