feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

f_templates/tpl_backend/tpl_settings/backend-menu-entry3-sub9.tpl

@@ -0,0 +1,28 @@
+	<link type="text/css" rel="stylesheet" href="{$main_url}/f_modules/m_backend/m_tools/m_linfo/layout/styles.css">
+	<link type="text/css" rel="stylesheet" href="{$main_url}/f_modules/m_backend/m_tools/m_linfo/layout/icons.css">
+	<script type="text/javascript" src="{$main_url}/f_modules/m_backend/m_tools/m_linfo/layout/scripts.js"></script>
+	<div class="wdmax" id="ct-wrapper">
+	    <form id="ct-set-form" action="">
+	    	<div class="page-actions" style="display: none;">{include file="tpl_backend/tpl_settings/ct-save-open-close.tpl"}</div>
+	    	<div class="clearfix"></div>
+		<div id="system-info-wrap" class="left-float wd738 top-bottom-padding ">{lang_entry key="backend.menu.entry3.sub9.system"}</div>
+		<input type="hidden" name="ct_entry" id="ct_entry" value="">
+	    </form>
+	    <script type="text/javascript">
+		$("#system-info-wrap").mask("loading");
+		$.post("{href_entry key="be_system_info"}", function(data){ldelim}
+		    $("#system-info-wrap").html(data);
+		    
+		    $(".page-actions").clone(true).detach().insertAfter("#system-info-wrap > div.header").show();
+		    
+		    var s = document.createElement("script");
+		    s.type = "text/javascript";
+		    s.src = "{$main_url}/f_modules/m_backend/m_tools/m_linfo/layout/settings-accordion.js";
+		    $("head").append(s);
+		    
+		    resizeDelimiter();
+		    $("#ct-wrapper").unmask();
+		{rdelim});
+	    </script>
+	</div>
+	{include file="tpl_backend/tpl_settings/ct-switch-js.tpl"}