message: Create the completions directory for fish before copying files
  Without this, the integrate command fails if the user did not
  already create the directory
diff: @@ -539,9 +539,26 @@ With a project open, go to Tools->NuGet Package Manager->Package Manager Console
  fish_completions_path = home_path / ".config";
  }
  - fish_completions_path = fish_completions_path / "fish/completions/vcpkg.fish";
  + fish_completions_path = fish_completions_path / "fish/completions";
  auto& fs = paths.get_filesystem();
  +
  + std::error_code ec;
  + fs.create_directories(fish_completions_path, ec);
  +
  + if (ec)
  + {
  + print2(Color::error,
  + "Error: Failed to create fish completions directory: ",
  + fish_completions_path,
  + ": ",
  + ec.message(),
  + "\n");
  + Checks::exit_fail(VCPKG_LINE_INFO);
  + }
  +
  + fish_completions_path = fish_completions_path / "vcpkg.fish";
  +
  if (fs.exists(fish_completions_path, IgnoreErrors{}))
  {
  vcpkg::printf("vcpkg fish completion is already added at %s.\n", fish_completions_path);
  