Register crater emoji via ui folder

#1458

core/src/mindustry/content/Items.java

@@ -7,7 +7,7 @@ import mindustry.type.ItemType;
 
 public class Items implements ContentList{
     public static Item scrap, copper, lead, graphite, coal, titanium, thorium, silicon, plastanium, phasefabric, surgealloy,
-    sporePod, sand, blastCompound, pyratite, metaglass, crater;
+    sporePod, sand, blastCompound, pyratite, metaglass;
 
     @Override
     public void load(){
@@ -97,10 +97,5 @@ public class Items implements ContentList{
             flammability = 1.4f;
             explosiveness = 0.4f;
         }};
-
-        // this is just to add the crater emoji, can't live without <3
-        crater = new Item("crater", Color.valueOf("989aa3")){
-            public boolean isHidden(){return true;}
-        };
     }
 }

core/src/mindustry/world/blocks/distribution/CraterConveyor.java

@@ -36,7 +36,7 @@ public class CraterConveyor extends BaseConveyor{
 
         start  = Core.atlas.find(name + "-5-0");
         end    = Core.atlas.find(name + "-6-0");
-        crater = Core.atlas.find("item-crater");
+        crater = Core.atlas.find("crater");
     }
 
     @Override