Add metaconfoundr to metaverse

[malcolmbarrett]

Is your package request related to adding features from other packages to the Metaverse? Please describe.

I am suggesting that our new package metaconfoundr, fresh on CRAN, is added to metaverse. metaconfoundr is a bias analysis tool similar to tools like ROBINS/robviz. It specializes in visualizing biases from confounding based on causal inference techniques based on a forthcoming methodology paper.

Where is the package located? CRAN, Github, etc
https://github.com/malcolmbarrett/metaconfoundr
https://malcolmbarrett.github.io/metaconfoundr/