Use dark mode Cursor icon on the new landing page

[Xurify]

I think the Cursor dark mode icon on the landing page would make more sense visually here

https://svgl.app/library/cursor_dark.svg
https://svgl.app/?search=Cursor
https://www.loftlyy.com/en/cursor

Before:

After:

[selvakumardhivakar]

I did work on this fix, having a PR ready.

[Xurify]

@selvakumardhivakar Nice nice!