Add v1 tag

[tadman]

Due to a limitation in the act tool, it'd be nice if there was a v1 tag as well as a branch.

Right now it's necessary to pin down to a specific version in order to use ruby/setup-ruby@...

[eregon]

Duplicate of #55.

Interestingly it seems allowed to have both a branch and tag of the same name, I find it very confusing though.

Anyway, I'm not moving tags, that's against the nature of tags of git.

[eregon]

FWIW actions/toolkit#631

[tadman]

Thanks for the clarification. This was less a complaint and more of a stub for other people with the same problem to find a solution. I couldn't find anything even after digging, so the link to #55 helps.