Better UMP support

[stan-osipov]

• Can you please add a tag to the repository? This way we can lock the package version via a tag. Without that we had to rely on the commit hash which is not very good. Plus some developers may not specify the commit hash and based on if `package-lock is committed into the repo or not they may end up with a different package version, which is far from ideal.
• Would be also nice to add the package to the OpenUPM or use npm.js as Scope Registry. This will make installation even more streamlined.
  Thank you!