Fixed serialize_example() example description and applied nbfmt

[eslam69]

This is a follow-up pull request regarding #2198, as @markmcd asked, I've run nbfmt on the notebook and passed nblint test locally.

• Fixed serialize_example() example description where the mentioned function create_message() was meant to be serialize_example().
• Updated the code cell where the serialize_example() is used, the example_observation variable was initialized but not used, so I filled it with the data, and used it as an argument to serialize_example().

[github-actions]

Preview

Preview and run these notebook edits with Google Colab:

• site/en/tutorials/load_data/tfrecord.ipynb

Rendered notebook diffs available on ReviewNB.com.

Format and style

Use the TensorFlow docs notebook tools to format for consistent source diffs and lint for style:

$ python3 -m pip install -U --user git+https://github.com/tensorflow/docs 
$ python3 -m tensorflow_docs.tools.nbfmt notebook.ipynb 
$ python3 -m tensorflow_docs.tools.nblint --arg=repo:tensorflow/docs notebook.ipynb 

If commits are added to the pull request, synchronize your local branch: git pull origin master

[8bitmp3]

@MarkDaoust

[eslam69]

Handled the merge conflict.

[eslam69]

@MarkDaoust Hello Mark, could you please review my work on the requested changes?

[8bitmp3]

@MarkDaoust @markmcd