Support JSON Resume Format

[rothnic]

The json resume format already includes an established schema and available rendering to html with various community created themes. It also can be extended with custom properties, which can be used for passing additional information to the agent, or controlling the output of the content.

[spencerthayer]

@rothnic I agree this is why I've made it the default format in my fork incidentally I've also merged most if not all of your pull requests into my fork.