Update existing Release notes template

• Update the number used in the multiexcerpt at the top of the release note page with the HF version number: 
  Unknown macro: { Unknown macro}
  Put 16 for 2021.16 for example.

Do a replace on the src/nxdoc/nuxeo-server/nuxeo-server-release-notes.md page to replace the previous version by the new one (nuxeo-server-updates-2021-18 => nuxeo-server-updates-2021-19, nuxeo-server-release-notes-2021-18 => nuxeo-server-release-notes-2021-19).

• Update <i class=fa fa-long-arrow-right aria-hidden=true> to <i class="fa fa-long-arrow-right" aria-hidden="true">

Code generating that is on draft-release-upgrade-notes.groovy.

• Remove "internal" tickets from RN 

Update the JIRA queries to remove internal tickets AND level = "Public"

• Convert code block correctly

For example code blocks here NXP-31279 are displayed like this:

The query parameter is , see below a cURL example:

The HTTP header is , see below a cURL example:

This information can then be retrieved in the extended object of audit entry under the name .