Improving Documentation

[Soft]

Nitro is currently lacking in documentation, this should be improved. I am creating this issue to track the progress of documentation project.

As of what the documentation should contain, as a starting point, I think we should have:

• Basic API Documentation: Basic documentation of classes and functions.
• Higher-Level Description of Project Structure: What are the different components and the relationships between them.
• Example Usage: It could be nice if we had some simple examples of how the framework could be used. How to write new backends etc.

[Soft]

I've been writing basic api documentation on a separate branch that is based on my multiple backends work as I hope it gets eventually merged. The current progress can be seen here.

[Soft]

Just to update this issue accordingly, I think most of the things described here have been done. Of course you could still have more documentation and the existing documentation could probably use a complete read through to spot any missing things, broken sentences, and remaining typos.