Enhance jekyll template for swagger documents

[kshychko]

Please add a render of definitions from swagger documents.
Each child element of "Definitions" represents a model, which needs to be displayed.
Please find a way how it can be rendered as pretty-JSON (as we do for examples).

If a model has an example property, it would be a either "application/json" or "application/xml" property with a string value. An example should be rendered separately from the model.

Each definition has e unique name and should be used for anchors, so we can refer to an example or a model.