doc/check-routeros-update: update notifications

doc/check-routeros-update.d/notification-01-found.avif
----- >8 -----
[rsc] ✨️ RouterOS update: 7.20.4

A new RouterOS version 7.20.4 is available for rsc.

Hostname:       rsc
Hardware:
    Board:      hAP ax^2
    Arch:       arm64
    Model:      C52iG-5HaxD2HaxD
    Serial:     HEG08Q4FT32
    License:    level 4
RouterOS:
    Channel:    stable
    Installed:  7.20.2
    Available:  7.20.4
RouterOS-Scripts:
    Commit:     main/3287/699be25b
    Version:    138

🔗️ https://mikrotik.com/download/changelogs/stable-release-tree
----- >8 -----

doc/check-routeros-update.d/notification-02-neighbor.avif
----- >8 -----
[rsc] ✨️ RouterOS update: 7.20.4

Seen a neighbor (MikroTik) running version 7.20.4 from stable, updating on rsc...

🔗️ https://mikrotik.com/download/changelogs/stable-release-tree
----- >8 -----

doc/check-routeros-update.md

@@ -35,9 +35,10 @@ automatically is supported.
 > to your production environment! Automatic updates should be handled
 > with care!
 
-### Sample notification
+### Sample notifications
 
-![check-routeros-update notification](check-routeros-update.d/notification.avif)
+![check-routeros-update notification found](check-routeros-update.d/notification-01-found.avif)  
+![check-routeros-update notification neighbor](check-routeros-update.d/notification-02-neighbor.avif)
 
 Requirements and installation
 -----------------------------