✨ Add [#examples ...] directive

[johannchopin]

The initial idea come from https://github.com/APIs-guru/graphql-faker where you can define an array of possible values to use. Could be nice to have such a syntax in restapify like:

{
  "name": "[#example 'Jojo' 'Luna']",
  "emails": "[#examples '[email protected]' '[email protected]' '[email protected]']"
}

...that will produce for example:

{
  "name": "Luna",
  "emails": ["[email protected]", "[email protected]"]
}

• "[#example ...]" should only return a single value
• "[#examples ...]" should return a random amount of items in a array between 1 and the list length without containing duplicates
• No need of casting syntax here -> if you need a boolean or number value don't wrap it between a '