Meta description option

https://github.com/FreshRSS/FreshRSS/issues/1105

app/Models/Context.php

@@ -144,11 +144,13 @@ class FreshRSS_Context {
 		case 'a':
 			self::$current_get['all'] = true;
 			self::$name = _t('index.feed.title');
+			self::$description = self::$system_conf->meta_description;
 			self::$get_unread = self::$total_unread;
 			break;
 		case 's':
 			self::$current_get['starred'] = true;
 			self::$name = _t('index.feed.title_fav');
+			self::$description = self::$system_conf->meta_description;
 			self::$get_unread = self::$total_starred['unread'];
 
 			// Update state if favorite is not yet enabled.

data/config.default.php

@@ -27,6 +27,9 @@ return array(
 	# Title of this FreshRSS instance in the Web user interface.
 	'title' => 'FreshRSS',
 
+	# Meta description used when `allow_robots` is true.
+	'meta_description' => '',
+
 	# Name of the user that has administration rights.
 	'default_user' => '_',