Add support for super class

[joaobispo]

Documentation model does not store information about super classes of classes.

• For JS code that information is in the AST;
• For LARA code that information would have to be extracted (but not might be needed if .lara is transformed into .js in the future);
• There should be a link between the super and the destination class, if it exists in the documentation model. This could be a post-processing step;