Fix issues in create_tuned_model.md

[nidhinpd-YML]

Description of the change

Updated markdown to add HTML tags to work inside table cells

Motivation

The details especially for training_data was not readable at all. List and sub list all came under a single sentence. Had to check the comments in code to understand what the doc meant.

Type of change

Documentation

Checklist

• I have performed a self-review of my code.
• I have added detailed comments to my code where applicable.
• I have verified that my change does not break existing code.
• My PR is based on the latest changes of the main branch (if unsure, please run git pull --rebase upstream main).
• I am familiar with the Google Style Guide for the language I have coded in.
• I have read through the Contributing Guide and signed the Contributor License Agreement.

[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.

[MarkDaoust]

Hi, thanks for taking the time to send this change.

One problem here is that these files are generated, so regenerating them will revert these changes.

Another problem is that the source code is used to generate these files has inline markdown that we're inserting into the table cells.

So for an actual fix for the GH viewer we need to find a way to convince it to parse markdown inside the HTML table.

Quick testing shows that the easiest thing is to convince it that the table's help is in a markdown block.

• Start with a non-breaking space (the line doesn't start with html -> must be Markdown)
• Don't put line breaks between HTML elements (lines all start with markdown.)

 <table class="responsive fixed orange"><tr><td>`training_data`<a id="training_data"></a></td><td>The dataset to tune the `model on`. 
 
 * This must be either</td></tr></tr></table>

This fix would need to go into the tensoprflow_docs tool we're using here.

[MarkDaoust]

This is fixed by: #602