Explain how main menu promos work on Atlas (#112)

and list low quality versions of all spotlight images for quick reference

docs/Wiki/development/repositories/atlas.md

@@ -5,3 +5,76 @@ description: A new Northstar master server written in Go
 # Atlas
 
 TODO
+
+## Main menu promos
+
+For defining main menu promos shown to players, Atlas sends a JSON that defines them.
+
+The endpoint for this is `/client/mainmenupromos`
+
+```json
+{
+    "newInfo": {
+        "Title1": "%$rui\/bullet_point%`2Northstar vX.Y`0 is now live!",
+        "Title2": "%$rui\/bullet_point%`2Highlighted`0 defailt",
+        "Title3": "%$rui\/bullet_point%Make sure to `2update`0 your game!"
+    },
+    "largeButton": {
+        "Title": "Blog Title",
+        "Text": "Short Summary",
+        "Url": "https://northstar.tf/blog/REPLACE-ME/",
+        "ImageIndex": 0
+    },
+    "smallButton1": {
+        "Title": "Join the Discord!",
+        "Url": "https://northstar.tf/discord",
+        "ImageIndex": 22
+    },
+    "smallButton2": {
+        "Title": "Check out the Northstar Wiki!",
+        "Url": "https://northstar.tf/wiki",
+        "ImageIndex": 12
+    }
+}
+```
+
+`ImageIndex` corresponds to the index of the corresponding spotlight + 1
+
+### Spotlights
+
+The spotlights are:
+
+| Name           | Image                                                                |
+| -------------- | -------------------------------------------------------------------- |
+| `spotlight_01` | ![spotlight_01](../../../_static/images/spotlights/spotlight_01.png) |
+| `spotlight_02` | ![spotlight_02](../../../_static/images/spotlights/spotlight_02.png) |
+| `spotlight_03` | ![spotlight_03](../../../_static/images/spotlights/spotlight_03.png) |
+| `spotlight_04` | ![spotlight_04](../../../_static/images/spotlights/spotlight_04.png) |
+| `spotlight_05` | ![spotlight_05](../../../_static/images/spotlights/spotlight_05.png) |
+| `spotlight_06` | ![spotlight_06](../../../_static/images/spotlights/spotlight_06.png) |
+| `spotlight_07` | ![spotlight_07](../../../_static/images/spotlights/spotlight_07.png) |
+| `spotlight_08` | ![spotlight_08](../../../_static/images/spotlights/spotlight_08.png) |
+| `spotlight_09` | ![spotlight_09](../../../_static/images/spotlights/spotlight_09.png) |
+| `spotlight_10` | ![spotlight_10](../../../_static/images/spotlights/spotlight_10.png) |
+| `spotlight_11` | ![spotlight_11](../../../_static/images/spotlights/spotlight_11.png) |
+| `spotlight_12` | ![spotlight_12](../../../_static/images/spotlights/spotlight_12.png) |
+| `spotlight_13` | ![spotlight_13](../../../_static/images/spotlights/spotlight_13.png) |
+| `spotlight_14` | ![spotlight_14](../../../_static/images/spotlights/spotlight_14.png) |
+| `spotlight_15` | ![spotlight_15](../../../_static/images/spotlights/spotlight_15.png) |
+| `spotlight_16` | ![spotlight_16](../../../_static/images/spotlights/spotlight_16.png) |
+| `spotlight_17` | ![spotlight_17](../../../_static/images/spotlights/spotlight_17.png) |
+| `spotlight_18` | ![spotlight_18](../../../_static/images/spotlights/spotlight_18.png) |
+| `spotlight_19` | ![spotlight_19](../../../_static/images/spotlights/spotlight_19.png) |
+| `spotlight_21` | ![spotlight_21](../../../_static/images/spotlights/spotlight_21.png) |
+| `spotlight_22` | ![spotlight_22](../../../_static/images/spotlights/spotlight_22.png) |
+| `spotlight_23` | ![spotlight_23](../../../_static/images/spotlights/spotlight_23.png) |
+| `spotlight_24` | ![spotlight_24](../../../_static/images/spotlights/spotlight_24.png) |
+| `spotlight_25` | ![spotlight_25](../../../_static/images/spotlights/spotlight_25.png) |
+| `spotlight_26` | ![spotlight_26](../../../_static/images/spotlights/spotlight_26.png) |
+
+!!! note
+    These images are lower scaled version of the originals.
+    For the high quality original images, check the game files.
+
+!!! note
+    `spotlight_20` does not seem to exist