Add Amazon processed dataset

[s2kumar2007]

This PR adds a cleaned and processed subset of the Amazon Fine Food Reviews dataset.

Changes:

• Removed text-heavy columns
• Engineered numeric features for probabilistic modeling
• Converted dataset to tab-separated format
• Structured folder as real/amazon/data/

The dataset is suitable for structure learning and Bayesian modeling experiments.

the checklist for this PR

• Have you followed all the steps from our Contributing Guide?
• Does the PR fully address the linked issue and is within its defined scope? If you are still working on the PR, mark it as draft.
• Are all the GitHub Actions checks passing? If not, mark your PR as draft while you fix it.
• PR Was written manually.

Now i am adding a dataset in next Pull request i will added Amazon fine Food code files in main repositories

[s2kumar2007]

Any problem in this data set.Please let me know if any changes or guidelines need to be followed.

[s2kumar2007]

If this dataset is merged, I will create a pull request to add amazon.py to the datasets folder in pgmpy.

[DARHWOLF]

@s2kumar2007, I think someone is already working on this. You did not have yourself assigned an issue for adding this dataset. May I request you to follow the contributor guidelines, and perhaps take up an issue that isn't already assigned.
If the person working on this does not raise a PR, you could continue with this.

[s2kumar2007]

@DARHWOLF now , the work is assigned to me for adding amazon Dataset .If this dataset is merged, I will create a pull request to add amazon.py to the datasets folder in pgmpy.

[s2kumar2007]

@ankurankan now , the work is assigned to me for adding amazon Dataset .If this dataset is merged, I will create a pull request to add amazon.py to the datasets folder in pgmpy.

[ankurankan]

@s2kumar2007 Can you add the PR checklist back?

[s2kumar2007]

@ankurankan i have added The Checklist

[DARHWOLF]

Thanks. May I request the following:

• Add a readme to this directory which should describe the dataset and contain relevant details.
• Add this dataset to the repository's readme
• Add the license file to this directory

Please have a look at recently merged PRs for reference.