Add documentation section with commands to query the cache

m/module/hut-substituter.nix

@@ -4,7 +4,7 @@
     # Don't add hut as a cache to itself
     assert config.networking.hostName != "hut";
     {
-      trusted-substituters = [ "https://jungle.bsc.es/cache" ];
+      substituters = [ "https://jungle.bsc.es/cache" ];
       trusted-public-keys = [ "jungle.bsc.es:pEc7MlAT0HEwLQYPtpkPLwRsGf80ZI26aj29zMw/HH0=" ];
     };
 }

web/content/hut/_index.md

@@ -39,7 +39,6 @@ enable it for all builds in the system.
 { ... }: {
   nix.settings = {
     substituters = [ "https://jungle.bsc.es/cache" ];
-    trusted-substituters = [ "https://jungle.bsc.es/cache" ];
     trusted-public-keys = [ "jungle.bsc.es:pEc7MlAT0HEwLQYPtpkPLwRsGf80ZI26aj29zMw/HH0=" ];
   };
 }
@@ -61,7 +60,7 @@ Note: you'll have to be a trusted user.
 If using nix outside of NixOS, you'll have to update `nix.conf`
 
 ```
-# echo "trusted-substituters = https://jungle.bsc.es/cache" >> /etc/nix/nix.conf
+# echo "substituters = https://jungle.bsc.es/cache" >> /etc/nix/nix.conf
 # echo "trusted-public-keys = jungle.bsc.es:pEc7MlAT0HEwLQYPtpkPLwRsGf80ZI26aj29zMw/HH0=" >> /etc/nix/nix.conf
 ```