Update the docs on ACL tag's owners and OAuth client scopes

[longngn]

I'm trying to setup Tailscale on Github Actions according to this docs: https://tailscale.com/kb/1276/tailscale-github-action However, it's missing what the OAuth token scopes should be and what the tag owners for tag:ci should be According to some issues here in this repo, we only need devices:write for OAuth token and "tag:ci": [] and I will try it, but it's still better to update these in the docs

[jonashaag]

Would be nice if this was added to the docs!