Use @inherits in roxygen to simplify documentation

[AngusMcLure]

We can use @inherits to simplify the documentation of functions like design_effect and optimise_X since these functions reuse many of the arguments used in fi_pool and fi_pool_cluster. In general I think the @inherits should follow the dependency graph, i.e. document the parameters in the lowest (exported) function that uses that argument, and then use @inherits to propagate them through the docs

This will ensure consistent documentation across function and reduce the number of places we need to edit if we want to change something in the docs.

Not urgent, but helpful

[fredjaya]

Agree! Planning on doing it in the next round of improving documentation 😎https://github.com/AngusMcLure/PoolPoweR/blob/2e4878e15b389cca8c150fe5158c460220280384/CHANGELOG.md?plain=1#L32

[AngusMcLure]

Awesome!