port configuration for local modrinth modpack setup (#3116)

examples/modrinth/local-modpack/docker-compose.yml

@@ -7,9 +7,11 @@ services:
       # Download the mrpack file from https://modrinth.com/modpack/cobblemon-fabric/version/1.4.1 and place in
       # modpacks directory next to this compose file.
       MODRINTH_MODPACK: /modpacks/Cobblemon Modpack [Fabric] 1.4.1.mrpack
+    ports:
+      -  "25565:25565"
     volumes:
       - mc-data:/data
       - ./modpacks:/modpacks:ro
 
 volumes:
-  mc-data: {}
+  mc-data: {}