Docs Main summary file updated with links to every other document in …

…repo/doc (#2264)

doc/SUMMARY.md

@@ -5,9 +5,18 @@
   - [Nix](./installation_nix.md)
 - [Style guidelines](./style/summary.md)
     - [UltimateCataclysm (UltiCa)](./style/UltimateCataclysm/summary.md)
+        - [General info](./style/UltimateCataclysm/general.md)
+        - [Terrain/Furniture](./style/UltimateCataclysm/terrain-furniture.md)
+        - [Creatures](./style/UltimateCataclysm/creatures.md)
+        - [Overlays](./style/UltimateCataclysm/overlay.md)
+        - [Items](./style/UltimateCataclysm/items.md)
     - [MShockXotto+](./style/MShockXotto+/SUMMARY.md)
+        - [General info](./style/MShockXotto+/readme.md)
     - [HollowMoon](./style/HollowMoon/SUMMARY.md)
-
+        - [General info](./style/HollowMoon/readme.md)
+        - [Terrain](./style/HollowMoon/terrain.md)
+        - [Walls](./style/HollowMoon/walls.md)
+        - [Overlay](./style/HollowMoon/overlay.md)
 - [How to](./how-to/summary.md)
     - [Tileset structure](./how-to/structure.md)
     - [Autotiles/Multitiles](./how-to/autotiles.md)