gold formula adjusted for new meta (#757)

## Description: 
Gold formula adjusted to form ~ workers ^ .7

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

1brucben

src/core/configuration/DefaultConfig.ts

@@ -703,7 +703,7 @@ export class DefaultConfig implements Config {
   }
 
   goldAdditionRate(player: Player): number {
-    return Math.sqrt(player.workers() * player.numTilesOwned()) / 200;
+    return 0.045 * player.workers() ** 0.7;
   }
 
   troopAdjustmentRate(player: Player): number {