Fix[bta_profile]: set custom game directory

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/modloaders/BTADownloadTask.java

@@ -83,6 +83,8 @@ public class BTADownloadTask implements Runnable {
         MinecraftProfile btaProfile = new MinecraftProfile();
         btaProfile.lastVersionId = btaVersionId;
         btaProfile.name = "Better than Adventure!";
+        // Allows for smooth upgrades
+        btaProfile.gameDir = "./custom_instances/better_than_adventure";
         btaProfile.icon = tryDownloadIcon();
         LauncherProfiles.insertMinecraftProfile(btaProfile);
         LauncherProfiles.write();