added global shedrc option configuration to the nixos module

extracted options and rc file renderer into their own files

nix/module.nix

@@ -4,18 +4,11 @@ let
   cfg = config.programs.shed;
 in
 {
-  options.programs.shed = {
-    enable = lib.mkEnableOption "shed shell";
-
-    package = lib.mkOption {
-      type = lib.types.package;
-      default = pkgs.shed;
-      description = "The shed package to use";
-    };
-  };
+  options.programs.shed = import ./shed_opts.nix { inherit pkgs lib; };
 
   config = lib.mkIf cfg.enable {
     environment.systemPackages = [ cfg.package ];
     environment.shells = [ cfg.package ];
+    environment.etc."shed/shedrc".text = import ./render_rc.nix lib cfg;
   };
 }