Nice histogram visualization for the l_inf example

**Is your feature request related to a problem? Please describe.**
The visualization of L_inf in the first notebook looks bad

**Describe the solution you'd like**
2 heatmaps with meaningful axes instead of the 3d plots

**How important is it for you**
On a scale from 0 - nice to have to 5 - the library is almost unusable without it
This is 2 - The notebook would be quite a bit clearer?