feature request: easy way to make pyrec object if recall matrix data already exists

[andrewheusser]

support the creation of a pyrec data object with the recall matrix precomputed. currently, we dont store the recall matrix in the pyrec data object (we compute it on the fly), since some analyses do not depend on it.

I propose creating a helper function (e.g. recmat2pyro) that creates a pyro given a recall matrix, since other using this package might already have recall matrices computed, but want to use the package for other analyses/plotting. For example:

import pyrec as pyr
pyro = pyr.recmat2pyro(recmat)

would take a precomputed recmat and create a pyro object

[andrewheusser]

added in e091abd