Incorrect definition and examples for the stereotype field

[pedropaulofb]

The current provided definition for the stereotype field is:

stereotypes: A non-empty array of non-empty strings representing stereotypes of its container object. Nullable.

The term is in the plural form and it is an array. All examples provided in the README file follows this definition.

However, the current implementation of the ontouml-vp-plugin exports to the ontouml-schema using stereotype (singular term) and as a string field.