Reduce vertical and horizontal spacing around datasets in docs

[stefmolin]

Some of the details are lost with the current padding (see the gorilla in #221):

I would like to reduce the vertical and horizontal spacing so that we have a "closer" view of the dataset. This can probably be done by "chopping off" a bit of the xlim and ylim:

https://github.com/stefmolin/data-morph/blob/a93e627f133617d8405ad9319e7842fc5d176627/src/data_morph/data/loader.py#L165-L166