fix: fix the flake producing errors on check and when trying to access the templates output

flake.nix

@@ -20,15 +20,35 @@
     };
   };
 
-  outputs = {flake-parts, ...} @ inputs:
+  outputs = {
+    self,
+    flake-parts,
+    ...
+  } @ inputs:
     flake-parts.lib.mkFlake {inherit inputs;} {
       imports = [
-        flake-parts.flakeModules.flakeModules
-
         ./cad
         ./rust
+
+        flake-parts.flakeModules.flakeModules
+        # define the flake.templates option
+        ({lib, ...}: {
+          options.flake.templates = lib.mkOption {
+            type = lib.types.lazyAttrsOf (lib.types.submodule {
+              options = {
+                path = lib.mkOption {type = lib.types.path;};
+                description = lib.mkOption {type = lib.types.str;};
+              };
+            });
+            default = {};
+          };
+        })
       ];
 
+      flake.flakeModule = {
+        imports = builtins.attrValues (builtins.removeAttrs self.flakeModules ["default"]);
+      };
+
       systems = ["aarch64-linux" "x86_64-linux" "aarch64-darwin" "x86_64-darwin"];
 
       perSystem = {pkgs, ...}: {formatter = pkgs.alejandra;};