pass in site description as well for potential themes to take advantage of

src/webserver.js

@@ -74,6 +74,7 @@ var express = require('express'),
 					cssSrc: meta.config['theme:src'] || nconf.get('relative_path') + '/vendor/bootstrap/css/bootstrap.min.css',
 					pluginCSS: plugins.cssFiles.map(function(file) { return { path: file } }),
 					title: meta.config.title || '',
+					description: meta.config.description || '',
 					'brand:logo': meta.config['brand:logo'] || '',
 					'brand:logo:display': meta.config['brand:logo']?'':'hide',
 					browserTitle: meta.config.title || 'NodeBB',