softloud/metabroom: broom methods for metafor::rma models

These methods were originally part of the [tidymeta::] by Malcolm. Charles wanted to learn about dev and had some tweaks to make to the glance function. She's bundled Malcolm's functions so they can take a look and see what needs doing to get this ported into the [broom::] package proper.

install.packages("remotes")
remotes::install_github("softloud/metabroom")