Change the theme for mars rover imagery page #399

[Gaurav-Kushwaha-1225]

Issue No. #399

Video/Screenshots (mandatory)

https://github.com/PranavBarthwal/cosmoXplore/assets/117214772/b4c69010-1c44-48bc-9749-ab676d328752

Checklist:

• [X] I have mentioned the issue number in my Pull Request.
• [ ] I have commented my code, particularly in hard-to-understand areas
• [X] I have gone through the contributing.md file before contributing