message: (Update the README example with the new File API)
diff: @@ -44,7 +44,7 @@ fn main() -> hdf5::Result<()> {
  {
  // write
  - let file = hdf5::File::open("pixels.h5", "w")?;
  + let file = hdf5::File::create("pixels.h5")?;
  let colors = file.new_dataset::<Color>().create("colors", 2)?;
  colors.write(&[RED, BLUE])?;
  let group = file.create_group("dir")?;
  @@ -56,7 +56,7 @@ fn main() -> hdf5::Result<()> {
  }
  {
  // read
  - let file = hdf5::File::open("pixels.h5", "r")?;
  + let file = hdf5::File::open("pixels.h5")?;
  let colors = file.dataset("colors")?;
  assert_eq!(colors.read_1d::<Color>()?, arr1(&[RED, BLUE]));
  let pixels = file.dataset("dir/pixels")?;
  