Fix of polish description

During my plays I've noticed that it gives you a little bit too much resources so I descresed it.

For Cardbon/Iron:
Lvl 2 gives 3.75
Lvl 3 gives 6.5

For Rare:
Lvl 2 gives 3.25
Lvl 3 gives 5

Energy consumption stays the same.

Changed values to make it more efficient per level.
Additionaly miners now extract much more from node.

Before, each mine takes 1, now it takes like this:
For Carbon and Iron (per level):
TAKES: 1.85 -> 1.65 -> 1.4
GIVES: 2 -> 4.5 -> 10

For Rare:
TAKES: 1.75 -> 1.7 -> 1.65
GIVES: 1.75 -> 3.75 -> 8