Update v0.15

I'm excited to introduce the latest update! This update brings several key changes that will make your gameplay even more engaging. You'll need to manage your resources more carefully and take a more strategic approach. Here are the details:

• Various resources are now required to purchase upgrades, research, or other items. This change encourages a more tactical approach and requires better resource management.
  
• Asteroids and moons have been adjusted to match different danger levels.
  
• Tutorial texts have been updated to provide a better onboarding experience.
  
• Galactic trade updated: Collectible resources can now only be sold, not purchased.
  
• Balancing adjustments for various costs.
  
• Tutorial UI updated for a more user-friendly experience.
  
• Fixed a bug with the star map where searching for sectors no longer increases the star map level.
  
• Fixed a bug in the tutorial that prevented progress.