message: Minor fix to snapshot documentation to add snapshot path as positional argument
diff: @@ -284,7 +284,7 @@ def snapshot(path, compression="AUTO", reader_func=None, shard_func=None):
  ```python
  dataset = ...
  dataset = dataset.enumerate()
  - dataset = dataset.apply(tf.data.experimental.snapshot(
  + dataset = dataset.apply(tf.data.experimental.snapshot("/path/to/snapshot/dir",
  shard_func=lambda x, y: x % NUM_SHARDS, ...))
  dataset = dataset.map(lambda x, y: y)
  ```
  @@ -308,7 +308,7 @@ def snapshot(path, compression="AUTO", reader_func=None, shard_func=None):
  # read datasets in parallel and interleave their elements
  return datasets.interleave(lambda x: x, num_parallel_calls=AUTOTUNE)
  - dataset = dataset.apply(tf.data.experimental.snapshot(
  + dataset = dataset.apply(tf.data.experimental.snapshot("/path/to/snapshot/dir",
  reader_func=user_reader_func))
  ```
  