Add Ontology as MaMMoS' tool

[santaep]

For those, who doesn't need entity top and could use just the ontology, maybe would make sense to list ontology separately on the main page of MaMMoS, somewhere in additional tools or smth?

[lang-m]

I agree, a direct link to the ontology would be good.

I would propose to add a new section MaMMoS Ontology (or similar) to the landing page (similar to how we have MaMMoS Framework Software and Additional Tools). We should describe the ontology in a few sentences, link to the separate page and point to mammos-entity to work with the ontology in Python.