Add dark mode

[Raksha25]

Create a button that will switch between the original theme and the new theme.

[rezaduha]

hi, i would like to work on this issue

[Daksh-404]

Hi, I want to work on this issue!

[Raksha25]

@Daksh-404 @rezaduha you both can work on this.

[shantanuSakpal]

Hello, i would like to contribute my skills to solve this issue.