Added 3D Surface Plotter Calculator

[pandeyji711]

Fixes Issue🛠️

Closes #1245

Description👨‍💻

• Added : Plot 3D surfaces for given functions.
• Inputs: Function definition in two variables (x, y).
• Outputs: 3D plot of the surface, key points of interest (e.g., maxima, minima).

Type of Change📄

• New feature (non-breaking change which adds functionality)

Checklist✅

• I am an Open Source contributor
• I have performed a self-review of my code
• My code follows the style guidelines of this project

Screenshots/GIF📷

[github-actions]

Hey @pandeyji711, Welcome to the project CalcDiverse! 🎊
Thanks for your contribution! Your effort makes this project better. Keep it up! 🙌
Please wait for the PR to be reviewed. Happy Coding!! ✨

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[Rakesh9100]

Pls work on these by making the new commits in this same PR @pandeyji711

1. Rename your folder to 3D-Surface-Plotter-Calculator and make the necessary changes.
2. Rename app.js to script.js.
3. Add a README.md file of your calculator in your folder.

[pandeyji711]

@Rakesh9100 ok

[pandeyji711]

Pls work on these by making the new commits in this same PR @pandeyji711

1. Rename your folder to 3D-Surface-Plotter-Calculator and make the necessary changes.
2. Rename app.js to script.js.
3. Add a README.md file of your calculator in your folder.

@Rakesh9100

I have done all necessary changes.

[Nihal4777]

@Rakesh9100 This PR is reviewed & can be merged.

[github-actions]

Congrats, Your pull request has been successfully merged 🥳🎉 Thank you for your contribution to my project 🚀 Keep Contributing!! ✨ @pandeyji711