Standarise the way to publish releases

[Emily-Jiang]

Since spec html and pdf are not in maven central. In the past, the pdfs and htmls are attached to the releases. However, it is not convenient as they have to be downloaded for viewing.

In the recent release architecture changes, all of the docs and javadocs are uploaded to here. When releasing MicroProfile reactive messaging, I used the following format, which is much more user friendly.

I updated MicroProfile config to use this format. All other specs should adopt this format for improvement.

We also need to update microprofile.io to list all spec/pdf. I've filed this issue on microprofile-site repo.

[OndroMih]

Ideally, the Jenkins release job would use GitHub API to generate the description for the release, including links to Javadocs and spec documents and info about the maven artifact.

[Emily-Jiang]

done