Provide a func to conveniently (stressed) get a list of all available datasets

[Alvant]

or to get some very simple data information.

Because current get_info func:

from topicnet.dataset_manager import api

api.get_info()

is expected to be used only in Jupyter notebook (and I have doubts if at least someone will be able to do it the right way right away).

What I am talking about, is that it would be nice to have a func like this:

from topicnet.dataset_manager import api

api.get_datasets()  # ['postnauka', 'ruwiki_good', ...]

or make the aforementioned get_info be usable in terminal without this clumsy-dumpy HTML display stuff.

TL;DR We need a way to quickly and conveniently observe all the available datasets.