add a minimal dtml explantion page for integration tool

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@33084 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/dtml/explainIntegrationTool.dtml

+<dtml-var manage_page_header>
+<dtml-var manage_tabs>
+
+<p>Explain IntegrationTool</p>
+
+This tool is used to define integration sites.
+
+<dtml-var manage_page_footer>