[libnotify] notification: Add docs description for NotifyNotification

[Marco Trevisan <marcotrevi src gnome org>]

commit 8ce5daac4f3520a98ad3de8f95f9a52ad1b2e53b
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Tue Jun 7 03:09:48 2022 +0200

    notification: Add docs description for NotifyNotification

 libnotify/notification.h | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/libnotify/notification.h b/libnotify/notification.h
index 5706425..f1639d8 100644
--- a/libnotify/notification.h
+++ b/libnotify/notification.h
@@ -55,6 +55,11 @@ typedef struct _NotifyNotification NotifyNotification;
 typedef struct _NotifyNotificationClass NotifyNotificationClass;
 typedef struct _NotifyNotificationPrivate NotifyNotificationPrivate;
 
+/**
+ * NotifyNotification:
+ *
+ * A passive pop-up notification.
+ */
 struct _NotifyNotification
 {
         /*< private >*/