Update Donations.txt

Added:
ShadowMachine (STEAM_0:0:11736481) 15/07 to 15/08 | Donated 3$
Removed:
DJ Sirenwulf 08/05 to 22/07 | Donated £3 | EXTENDED (admin now)
TheDarkOneHD 07/06 to 07/07 | Donated €5 using PaySafe (over)
Nick Mason (STEAM_0:0:51229547) 14/06 to 14/07 | Donated £3 (over)