add a tutorial for editing and creating ontologies

[pablo-de-andres]

This is mentioned in the first tutorial, but no tutorial is available yet.

[harrytodorov]

I guess properly discussing how to create an ontology is a complicated (and to some extent ambiguous) process, thus boiling this down into easy to follow steps can be tricky

[pablo-de-andres]

That's why this issues has been there for a while 😅
I think it will gain importance when OSP-core supports direct interaction with the ontology triples