Add non-technical description of OrbitDB

[sirfumblestone]

It would be great to see also a non-technical description of OrbitDB (e.g. key features and capabilities). At the moment they might not be that evident if you are not experience developer and familiar with database models/types. I believe this kind of information would serve well people who are not so much (at least not yet) into database internals but are on quest of finding new tech 🖖

[sirfumblestone]

Would it make sense to add a bit more verbose description to README?

[RichardLitt]

I think that this could go in a Background section above the Usage section. But I'm not sure that this needs to be expounded upon in great depth in this repository, in general. I think it might belong in a blog post or in a tutorial, rather, or on an orbitdb-related website.

[aphelionz]

Resolved via the Field Manual. Feel free to open any tickets there in case that section is unclear