highlight skin used to render site and documents statistics

[INFO] --- maven-site-plugin:3.7:site (default-site) @ maven-site ---
[INFO] configuring report plugin org.apache.maven.plugins:maven-project-info-reports-plugin:2.9
[INFO] 21 reports configured for maven-project-info-reports-plugin:2.9: index, summary, dependency-info, modules, project-team, scm, issue-tracking, mailing-list, dependency-management, dependencies, dependency-convergence, cim, plugin-management, plugins, distribution-management, index, project-team, mailing-list, scm, issue-tracking, cim
[INFO] Relativizing decoration links with respect to localized project URL: https://maven.apache.org/
[INFO] Rendering site with org.apache.maven.skins:maven-fluido-skin:jar:1.7 skin.
[INFO] Skipped "About" report (maven-project-info-reports-plugin:2.9:index), file "index.html" already exists for the English version.
[INFO] Skipped "Source Code Management" report (maven-project-info-reports-plugin:2.9:scm), file "source-repository.html" already exists for the English version.
[INFO] Skipped "Issue Management" report (maven-project-info-reports-plugin:2.9:issue-tracking), file "issue-tracking.html" already exists for the English version.                 
[INFO] Rendering 197 Doxia documents: 142 apt, 4 fml, 41 markdown, 9 xdoc, 1 xhtml