Styleguide forms

Ok, before I'm tempted to do anymore tweaking, here's a styleguide update
- modifications to styleguide template
- updates to documentation for form anatomy
- example usage of crispy forms
- support for documentation generation straight from source using [pycco](https://github.com/fitzgen/pycco)
There's a typo here. Should say "An item *that* provides..." (emphasis added to highlight the change).