Docs: Cost function illustrations

[thorbjornwolf]

Super neat library! The API feels very well-designed 🤩

Reading the documentation, I miss a couple of things.
Another (after #275) is grokking the cost functions.
For me, plots work wonders, so I would love to be presented with a plot of a typical signal they would be useful on.
For instance, I imagine that CostLinear is useful for something like this:

I have no clue what the CostCLinear prototypical signal would look like, however 😄

Existing work

I see there's something in the Piecewise Gaussian generation page. It takes a little time to grok, but I got it now. I wish for something like this in the Cost function pages, too 🙏

[deepcharles]

Hi,

Thanks for the comment. Indeed, the documentation needs some improvement. I'll be sure to add your suggestion first. Certainly in Section "Gallery of examples".