Move v1 tag to latest v1.x release, similar for v2 tag

[mgeisler]

Hi there!

This is slightly related to the discussion in #1: I believe the v1 tag should be moved to point to the same commit as the v1.6 tag. Similarly, l believe it's good practice to have a v2 tag that would point to the same commit as the v2.2 tag.

This would make it possible for people to track the v2 line of releases. This in turn will lead to less churn for the wider community. Currently, they can only track a single tag and they're all different:

The GitHub documentation describes this in a bit more detail.