Fix spreadshirt link (#41)

Co-Authored-By: bruegeln <bruegeln@noreply.git.hacknology.de>
Co-Committed-By: bruegeln <bruegeln@noreply.git.hacknology.de>

config.toml

@@ -72,7 +72,7 @@ name = "Shop"
 pre = "<i class='fa fa-shopping-cart fa-fw'></i>"
 weight = 50
 identifier = "shop"
-url = "https://hacknology.spreadshirt.de"
+url = "https://shop.spreadshirt.de/hacknology/all"
 
 [[menu.main]]
 name = "Kontakt"