added git submodule

src/user/modules/git/scripts/cdg.nix

@@ -0,0 +1,24 @@
+''
+function cdg() {
+  if [[ $1 == "--help" ]]; then
+    echo "A simple utility for navigating to the root of a git repo"
+    return 0
+  fi
+
+  if [[ -n "$1" ]]; then
+    echo "Invalid command: $1. Try 'cdg --help'."
+    return 1
+  fi
+
+  local root_dir
+  root_dir=$(git rev-parse --show-toplevel 2>/dev/null)
+  local git_status=$?
+
+  if [ $git_status -ne 0 ]; then
+    echo "Error: Not a git repo."
+    return 1
+  fi
+
+  cd "$root_dir"
+}
+''