update README with GPLv3 license and badges

[ABHIRANJAN-KUMAR1]

Updated README.md to improve clarity, usability, and licensing information.

License

• Added GNU General Public License v3.0 (GPLv3) section.
• Clarified user permissions and contributor obligations.

Documentation & Structure

• Added badges for Gitpod, CI, chat, and donations.
• Included a Table of Contents for easy navigation.
• Reorganized sections: Overview, Features, Documentation, Installation, Quick Start, Algorithm Categories, Contributions, FAQ, License.

Examples & Instructions

• Provided installation steps for cloning and compiling C programs.
• Added a quick start example (Bubble Sort) with compilation and execution instructions.

Formatting & Readability

• Improved markdown formatting for better readability.
• Ensured all links and badges are functional.
• Made README copy-paste friendly for users and contributors.

Contribution Guidelines

• Included steps for branching, committing, and creating pull requests.

This commit makes README fully ready for users and contributors, ensuring clear guidance and legal clarity under GPLv3.

Description of Change

References

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• Relevant documentation/comments is changed or added
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

Notes:

[ABHIRANJAN-KUMAR1]

Hi

I’ve updated the README with GPLv3 license, badges, and structured layout.
Could you please review and approve the PR so it can be merged?

Thanks!