`aggregate_scores` not exported

[barryrowlingson]

This package has a few functions that aren't exported - should they be? In particular, aggregate_scores is well-documented but not exported, so not truly available to the package user. Some of the others might be the calculate_ functions.

It is documented on https://rdrr.io/cran/IMD/ but I think that site must be documenting exported and unexported functions...