refactor: added flake parts

modules/hosts/home/leyla/packages/git.nix

@@ -0,0 +1,16 @@
+{...}: {
+  flake.homeModules.leylaGit = {...}: {
+    config = {
+      programs = {
+        git = {
+          signing.format = "openpgp";
+          settings = {
+            user.name = "Leyla Becker";
+            user.email = "git@jan-leila.com";
+            init.defaultBranch = "main";
+          };
+        };
+      };
+    };
+  };
+}