Update and Convert Documentation for XWiki Installation on AWS

Update and convert doc for https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Installation/XWiki%20Installation%20on%20AWS/, check what to keep& update from https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Installation/XWiki%20Installation%20on%20AWS/Deployment%20Using%20Cloudformation%20Template/ and https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Installation/XWiki%20Installation%20on%20AWS/Deployment%20Using%20CDK%20Code/ (children pages).