Documentation - do or don't repeat yourself

[RaphaelS1]

The roxygen mantra is do repeat yourself in documentation. For inheritance this can get quite tedious. Whilst roxygen supports inherited methods, if we inherit every method down every tree, this could get very messy and with method overloading it could also be quite complicated. However, by not either inheriting (via docstrings) or adding each inherited method manually, the user is left to follow a chain of links to find all methods.

Which of the two do we opt for:

1. Do inherit methods in documentation, via roxygen or manually, leading to long and potentially confusing documentation.
2. Do not inherit methods, leading to short documentation with missing methods/variables but with links (possibly many) to point to the relevant method/variable documentation

[RaphaelS1]

This is forced by #46 and Roxygen documentation, each Class contains a table of links to the individual method help pages.