Adding style for publish Date

searx/static/css/style.css

 .result h3{font-size:1em;word-wrap:break-word;margin:5px 0 1px 0;padding:0}
 .result .content{font-size:.8em;margin:0;padding:0;max-width:54em;word-wrap:break-word;line-height:1.24}
 .result .url{font-size:.8em;margin:3px 0 0 0;padding:0;max-width:54em;word-wrap:break-word;color:#c0392b}
+.result .published_date{font-size:.8em;color:#888;margin:5px 20px}
 .engines{color:#888}
 .small_font{font-size:.8em}
 .small p{margin:2px 0}

searx/static/less/definitions.less

 // Url to result
 @color-result-url-font: #C0392B;
 
+// Publish Date
+@color-result-publishdate-font: #888;
+
 // Images
 @color-result-image-span-background-hover: rgba(0, 0, 0, 0.6);
 @color-result-image-span-font: #FFF;

searx/static/less/style.less

 		word-wrap:break-word;
 		color: @color-result-url-font;
 	}
+
+	.published_date {
+		font-size: 0.8em;
+		color: @color-result-publishdate-font;
+    	margin: 5px 20px;
+	}
 }
 
 .engines {