Add game_data_version (it's mostly for WE dev, ngl)

docs/scarpet/api/Auxiliary.md

@@ -488,7 +488,7 @@ it could either mean your input is wrong, or statistic effectively has a value o
 ### `system_info()`, `system_info(property)`
 Fetches the value of a system property or returns all inforation as a map when called without any arguments. It can be used to 
 fetch various information, mostly not changing, or only available via low level
-system calls. In all cirumstances, these are only provided as read-only.
+system calls. In all circumstances, these are only provided as read-only.
 
 Available options in the scarpet app space:
   * `app_name` - current app name or `null` if its a default app
@@ -506,7 +506,7 @@ Available options in the scarpet app space:
 
 
  Relevant gameplay related properties
-  * `game_difficulty` - current difficulty of the game: `'peacefu'`, `'easy'`, `'normal'`, or `'hard'`
+  * `game_difficulty` - current difficulty of the game: `'peaceful'`, `'easy'`, `'normal'`, or `'hard'`
   * `game_hardcore` - boolean whether the game is in hardcore mode
   * `game_storage_format` - format of the world save files, either `'McRegion'` or `'Anvil'`
   * `game_default_gamemode` - default gamemode for new players
@@ -514,6 +514,7 @@ Available options in the scarpet app space:
   * `game_view_distance` - the view distance
   * `game_mod_name` - the name of the base mod. Expect `'fabric'`
   * `game_version` - base version of the game
+  * `game_data_version` - data version of the game. Returns an integer, so it can be compared.
   
  Server related properties
  * `server_motd` - the motd of the server visible when joining

src/main/java/carpet/script/utils/SystemInfo.java

@@ -13,6 +13,7 @@ import carpet.settings.ParsedRule;
 import carpet.settings.SettingsManager;
 import com.sun.management.OperatingSystemMXBean;
 import net.fabricmc.loader.api.FabricLoader;
+import net.minecraft.SharedConstants;
 import net.minecraft.util.WorldSavePath;
 import net.minecraft.world.GameRules;
 
@@ -56,6 +57,7 @@ public class SystemInfo {
         put("game_view_distance", c -> new NumericValue(c.s.getMinecraftServer().getPlayerManager().getViewDistance()));
         put("game_mod_name", c -> StringValue.of(c.s.getMinecraftServer().getServerModName()));
         put("game_version", c -> StringValue.of(c.s.getMinecraftServer().getVersion()));
+        put("game_data_version", c->NumericValue.of(SharedConstants.getGameVersion().getWorldVersion()));
 
         put("server_ip", c -> StringValue.of(c.s.getMinecraftServer().getServerIp()));
         put("server_whitelisted", c -> new NumericValue(c.s.getMinecraftServer().isEnforceWhitelist()));