[PR] Gravity and Gravity Tethers

[Mikeistaken]

I think the station wide tether should have the amount of materials needed reduced

Reason for request:
Miners generally cant get Quill consistently and most people don't know that Erebite works as extraordinarily dense crystal, lowering this number will allow for another gravity tether to be made, especially when the miners get their full equipment and decide to go to some random place