Release process improvements

[miquelbeltran]

As discussed internally, the release process could be improved with the following:

• Each release should be tagged and a GitHub Release should be created, with an updated changelog.
• Versioning should be set in code and not in CI, e.g. as done with the Blazor provider using a version.props file.
• Document the release process in the repository itself, e.g. in a RELEASE.md file.
• Research if we can configure CI to upload the packages automatically when a new release is build.