Add custom dataset notebook

[Louis-Dupont]

No description provided.

[BloodAxe]

Pls update the install commands:

!pip install data-gradients==0.2.1 gwpy &> /dev/null
!pip install super-gradients==3.3.1 gwpy &> /dev/null
!pip freeze gwpy &> /dev/null

to

!pip install -qq super-gradients==3.3.1

(No need to specify DG version IMO since it's already in requirements)

[BloodAxe]

This #1607 should be merged before current PR

[Louis-Dupont]

Changing pip install ... 873d4e9

[BloodAxe]

Just a minor comment on the notebook - we don't need prettyformatter as pprint comes with a standard python 3.x (from pprint import pprint) so this dependency can be dropped from pip install list.

[BloodAxe]

LGTM