More documentation and examples

[trusktr]

Can we please get some more documentation besides a schema and the super basic example in the README?

For example maybe

• further examples in the examples folder would help,
• for example an example of a complex custom element that covers all of the use cases,
• including all the Types of usual attributes an element can have (number, string, boolean, etc), events (including onfoo properties, event types, etc),
• maybe examples of more complex types like Array<Foo | Bar> in a recommended format (like a reference implementation) that people should try to follow
• How to generate CEM
• etc