feat: add Simpson's rule numerical integration

[Jyo561]

Description

What is the purpose of this pull request?

This pull request:

• adds a Simpson's rule implementation for numerical integration
• provides a function to approximate definite integrals over a closed interval
• includes input validation, tests, and documentation

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• none

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request?

This contribution is part of my interest in extending numerical computing capabilities in stdlib, particularly in the areas of integration, differentiation, and differential equation solvers.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

I used AI tools (ChatGPT) to understand stdlib structure and assist with drafting the implementation, tests, and documentation. All changes were reviewed, adapted, and validated manually.

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@stdlib-js/reviewers

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[kgryte]

This entire PR is incorrect and simply copy-pasted math/base/special/sin while updating the main.js file, with an incorrect license comment, etc. As such, I am going to close. This is not what we are looking for.

[stdlib-bot]

Thank you for working on this pull request. However, we cannot accept your contribution as this pull request does not follow project conventions.

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