Improve documentation

[andypike]

There is a lot of documentation in the readme and I think it covers most things but think about improving the documentation:

• Add a wiki page for each component (Forms, Commands, Queries and Presenters)
• Trim down the readme to be more concise and link off to the wiki where required
• Add documentation to methods and publish API docs
• Add examples for popular use cases

Take a look at https://readthedocs.org/