DOCS:Adding a security.md file for disclosing vulnerabilities

[K-dev01]

hello @Xandar-Y,
This project, which turns pins into stickers, currently does not include a SECURITY.md file.

Adding a SECURITY.md would help define a clear and responsible process for reporting security vulnerabilities and align the repository with common open-source best practices.

Proposed Change

Add a SECURITY.md file at the root of the repository

Include basic guidelines for privately reporting security issues

Benefit

Improves project professionalism and ensures security concerns are handled responsibly.

[Shravani1016]

Hi @Xandar-Y 👋
I’d like to work on this issue and add a SECURITY.md file following GitHub’s security best practices.
Please assign this issue to me. Thanks!