Overview: Save mechanic, fixes, QoL and adjustments

Changes:

• Added a Save / Export / Load mechanic
• Moved settings to bottom of the page, as a footer and added a discord link.
• Fixed activities upgrades not being applied correctly, like for Meditate
• Greatly reduce drop rates on all zones to balance with 50x speed. This is so gameplay speed feels better.
• Changed so activities start at rank 0. Easier to track effects this way.
• Added missing activities from drop pool
• Adjusted some drop effects and upgrade requirements
• Modified realm up requirements for more sinergy with stats and drops
• Modified a few UI components for better visuals / gameplay
• Added tooltip descriptions to some fields and exploration zones