Update README.md for tf-nightly-cpu-2.0-preview hyperlink (#7879)

Author: gaikwadrahul8

tfjs-converter/README.md

@@ -24,7 +24,7 @@ __0. Please make sure that you run in a Docker container or a virtual environmen
  The script pulls its own subset of TensorFlow, which might conflict with the
  existing TensorFlow/Keras installation.
 
-__Note__: *Check that [`tf-nightly-2.0-preview`](https://pypi.org/project/tf-nightly-2.0-preview/#files) is available for your platform.*
+__Note__: *Check that [`tf-nightly-cpu-2.0-preview`](https://pypi.org/project/tf-nightly-cpu-2.0-preview/#files) is available for your platform.*
 
 Most of the times, this means that you have to use Python 3.6.8 in your local
 environment. To force Python 3.6.8 in your local project, you can install