Some additional changes based on feedback.

• Properly centered level titles.
• Added status bar with tooltips to clarify the conditions for each level.
• Rewrote tutorials and hints to be more explicit and consistent about symbols and syntax.
• Fixed typos.
• Hints can be read after choosing both a correct and incorrect door.
• Equality comparisons of guards are exclusive (either ✓, X, or 🎲).
• "✓ / 💬" and "X & 💬" tautologies don't show up as 🎲 in the logic grid.
• Improved logic grid header for lion and star doors and question-target guards.
• Self questioning re-enabled (and mentioned as alternative in Knave hint).