Update interface to remove redundant lines in imports and .api calls

[ibevers]

I propose updating the interface so that things like:
from senselab.audio.tasks.preprocessing.preprocessing import resample_audios and
from senselab.audio.tasks.speech_to_text.api import transcribe_audios
become:
from senselab.audio.tasks.preprocessing import resample_audios
from senselab.audio.tasks.speech_to_text import transcribe_audios
(respectively)

We can do this by editing init.py files.

[fabiocat93]

great idea. please do it. i think this is going to affect the way pdoc will structure and generate the documentation. please, make sure that all pages are still going to be included after this change