feat(c): init c template

templates/c/flake/formatter.nix

@@ -0,0 +1,20 @@
+{
+  writeShellApplication,
+  alejandra,
+  llvmPackages_19,
+  fd,
+}:
+writeShellApplication {
+  name = "formatter";
+  runtimeInputs = [
+    alejandra
+    llvmPackages_19.clang-tools
+    fd
+  ];
+  text = ''
+    fd --extension nix -X alejandra -- {}
+    fd --extension nix -X deadnix -e -- {}
+    fd --extension nix -x statix fix -- {}
+    fd --extension c -X clang-format --verbose -i -- {}
+  '';
+}