Make subsetting into a toggle.

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

lib.nix

@@ -61,6 +61,7 @@ let
     buildInputs = [
       hugo ruby stork agdaEnv pythonEnv
     ];
+    subset = lib.boolToString settings.subset;
   };
 in
   {
@@ -68,6 +69,7 @@ in
       inherit (settings) host;
       ssl = settings.ssl or false;
       drafts = settings.drafts or false;
+      subset = settings.subset or true;
       src = blog-source;
       path = ".";
     };