Include meta description if available

source/index.html.jade

@@ -4,6 +4,7 @@ html(ng-app="sideBySide" ng-controller="AppController")
 		base(href="#{base}")
 		title(ng-bind="title()") Side By Side viewer
 		meta(charset="utf-8")
+		meta(name="description", content="{{ description() }}")
 		link(rel="stylesheet", type="text/css", href="//fonts.googleapis.com/css?family=PT+Serif:400,700,400italic,700italic&subset=latin,latin-ext")
 		if html5Mode == true
 			script.

source/scripts/controllers/app.js.coffee

@@ -4,6 +4,9 @@ angular.module("sideBySide").controller "AppController",
 	$scope.title = =>
 		poems.config.title || 'Side By Side viewer'
 
+	$scope.description = =>
+		poems.config.description || ''
+
 	$scope.$watchCollection ->
 		poems.config
 	, ->