Make MonologueProcess an addon

[atomic-junky]

At present, to make a game with Monologue you have to write your own interpreter. So I think MonologueProcess should become an addon and have its own repository to make things easier. The editor would use this addon. This would make it much simpler to create a game with Monologue.

Then there could be other repositories for other game engines. That's why I think Monologue should be moved to an organization.

[atomic-junky]

I've created a new repo that contains the addon (in wip) and moved all the Monologue related repos into a new organisation

When the addon is ready, it can be integrated into Monologue.