chore: update landing and /about highlight pictures

They should also have higher resolution.

![Image](https://github.com/user-attachments/assets/a2a80d6a-fdf1-44d4-ba91-812f8d28a4ab)

![Image](https://github.com/user-attachments/assets/da72db13-a88e-46df-a581-c0e93a9ac9f8)