Add new article: Better documentation for user options to "Generic"

[mcguinlu]

At present, users can do a lot with the Generic template by passing arguments ot the ... argument of rob_*() functions - however, the arguments are not well documented. As an example, I recently had to go to the source code to find the correct argument name to change the judgment labels.

Solution: create a new article that describes the capabilities of the Generic template in detail.

See also #89