HSEARCH-1670 Clarify warning message on extension points needing a public contructor
HSEARCH-1671 Upgrade asciidoctor-maven-plugin to version 1.5.0
HSEARCH-1671 Polish and fix formatting of documentation, adjust to requirements of new Asciidoctor version
HSEARCH-1671 Link to nexus downloads for modules is misrendered and is missing version injection