docs: Add term entry for NumPy ndarray.copy()

[riyadey27]

Description

This PR adds a new term entry for the NumPy ndarray.copy() method.

The new file, content/numpy/concepts/ndarray/terms/copy/copy.md, explains what copy() does (creating an independent copy vs. a view), its syntax, parameters, return value, and includes both a standard example and a runnable Codebyte example, following the project's templates and style guides.

Issue Solved

Closes #7819

Type of Change

• Adding a new entry
• Editing an existing entry (fixing a typo, bug, issues, etc)
• Updating the documentation

Checklist

• All writings are my own.
• My entry follows the Codecademy Docs style guide.
• My changes generate no new warnings.
• I have performed a self-review of my own writing and code.
• I have checked my entry and corrected any misspellings.
• I have made corresponding changes to the documentation if needed.
• I have confirmed my changes are not being pushed from my forked main branch.
• I have confirmed that I'm pushing from a new branch named after the changes I'm making.
• I have linked any issues that are relevant to this PR in the Issues Solved section.

[CLAassistant]

All committers have signed the CLA.

[mamtawardhani]

Looks good for a second review! 🚀

[riyadey27]

Hello!
Please review.