message: Fix doc hyperlink.
diff: @@ -49,7 +49,7 @@ partially supported by TensorFlow Lite, and one would like to avoid those
  limitations.
  The following example shows how to use `target_ops` in the
  -[`TFLiteConverter`](./convert/python_api) Python API.
  +[`TFLiteConverter`](./convert/python_api.md) Python API.
  ```
  import tensorflow as tf
  