Add NHS-R as a funder to the package DESCRIPTION

[Moohan]

I was looking at this article for something else: https://r-pkgs.org/description.html#sec-description-authors-at-r and noticed there is a 'funder' role. It's my understanding that NHS-R provided funding for the initial development of this package, so should be acknowledged for that.

Something like:
person("NHS-R Community", , , , role = "cph") but we could reach out to see how they'd like to be referenced (include an email etc.)