Fix typos in Tensor tutorial guide

[Cyrax321]

Description

This PR fixes two documentation typos in the Tensor tutorial (site/en/guide/tensor.ipynb) as reported in tensorflow/tensorflow#115281.

Changes

1. Inconsistent terminology: Changed 2-rank tensor to rank-2 tensor in the "Multi-axis indexing" section to be consistent with the established convention used elsewhere in the document (e.g., "a matrix is rank 2", "rank-2 tensor" in the About shapes section).
2. Missing punctuation: Added a missing period in a code comment in the "String tensors" section:
3. • Before: # Tensors can be strings, too here is a scalar string.
4. • After: # Tensors can be strings, too. Here is a scalar string.

Related Issue

Fixes tensorflow/tensorflow#115281

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[github-actions]

Preview

Preview and run these notebook edits with Google Colab:

• site/en/guide/tensor.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 fix-tensor-tutorial-typos