In-game tips / tutorial

[bglw]

UI adds:

• Add quick start rules to game menu
• Battle notifications (notification drawer, each battle explained in depth)
• Rule explanation UI pattern

Onboarding game "learning puzzle":

• Spacious board
• Guaranteed usable player letters
• Guaranteed decent enough computer
• Altered computer that can look for an opportunity to swap

UI tutorial pop-ups:

• Explain where you can play for a few turns
• Explain opening the dictionary (before any battle)
• Explain the validity overlay
  • Trigger once board has some number of words
  • Explain whatever colors are present
  • If orange wasn't present, trigger an explanation whenever it later is
• Explain battle notifications
• Explain swapping after the first computer swap move
• "Close to winning" explanation

Rule pop-ups:

• Explosions
• Player truncation
• Attacking with valid + invalid words
• Losing an attack on validity
• Losing an attack on length
• Losing one of two words to an attack
• Attacking multiple words
• Losing to a town or an artifact