Add GSSoC'25 Banner

[Mimansha19-tech]

 Attracts GSSoC'25 contributors.

Shows official participation and builds trust.

Increases project visibility and community engagement.

Visibly supports diversity and inclusion in tech.

Provides immediate clarity for participants.

[premm0923]

Hello, I'm interested in working on this issue. Please assign it to me.

Also, do you have the official banner's Markdown/HTML snippet, or should I find it on the GSSoC '25 website?