feat(icons): add racknerd (#1044)

Co-authored-by: Dashboard Icons Manager <193821040+dashboard-icons-manager[bot]@users.noreply.github.com>

tree.json

@@ -1564,6 +1564,8 @@
         "qutebrowser.png",
         "r.png",
         "rabbitmq.png",
+        "racknerd-dark.png",
+        "racknerd.png",
         "radarr.png",
         "radicale.png",
         "rainloop.png",
@@ -5451,6 +5453,8 @@
         "qutebrowser.webp",
         "r.webp",
         "rabbitmq.webp",
+        "racknerd-dark.webp",
+        "racknerd.webp",
         "radarr.webp",
         "radicale.webp",
         "rainloop.webp",