Change length delta to 1

[bglw]

• [x] Add new rule generation
• [x] Add ability to pin rule generations to specific day releases
• [x] Regenerate daily puzzle to match rule generation days
• [x] Add changelog + tutorial to explain new rule
• [x] Update existing tutorial
• [x] Add ability to release changelog at a specific day
• [x] Update changelog system to a player relationship with each marked as read
• [ ] #287