For AUTO_CURSEFORGE, can auto-set LEVEL from world save provided by modpack (#1929)

examples/one-block-modded/docker-compose.yml

@@ -0,0 +1,19 @@
+version: "3.8"
+
+services:
+  mc:
+    image: itzg/minecraft-server
+    ports:
+      - "25565:25565"
+    environment:
+      EULA: "true"
+      TYPE: AUTO_CURSEFORGE
+      CF_PAGE_URL: "https://www.curseforge.com/minecraft/modpacks/one-block-modded/files/4136487"
+      CF_SET_LEVEL_FROM: OVERRIDES
+      DEBUG: "false"
+      MEMORY: 4G
+    volumes:
+      - mc-data:/data
+
+volumes:
+  mc-data: {}