[doc] Add pages from old "usage" section

docs/pages/pmd/userdocs/pmd_tools.md

@@ -7,4 +7,6 @@ folder: pmd/userdocs
 
 * IDE plugins
 * build tool plugins
+    *   [Ant Task Usage](/pmd_userdocs_ant.html)
+* [Continuous Integrations plugins](/pmd_userdocs_ci.html)
 * GUIs

docs/pages/pmd/userdocs/pmd_userdocs_ci.md

@@ -0,0 +1,26 @@
+---
+title: Continuous Integrations plugins
+sidebar: pmd_sidebar
+permalink: pmd_userdocs_ci.html
+folder: pmd/userdocs
+---
+
+## Introduction
+
+PMD can be integrate through some of the Continuous Integration tools that exist now.
+Here is a list of known (to us) plugin to do so.
+
+## Hudson Plugin
+
+Hafner Ullrich has developed a [PMD plugin][hudsonplugin] for Hudson.
+Please check the plugin homepage for more info.
+
+[hudsonplugin]: http://hudson.gotdns.com/wiki/display/HUDSON/PMD+Plugin
+
+## Continuum
+
+Continous does not have a plugin for PMD per see, but can failed the build according to the
+result of the PMD maven plugin.
+
+
+<!-- TODO: Find out about other plugins ? -->