Add multiple modalities to each set of "readings"

[ethanwhite]

Providing multiple ways for students to obtain information is good Universal Design for Learning. There are a ton of options for obtaining background on core R and data structure material, so each set of "readings" could include multiple options: either watch this set of videos or read this chapter of Hadley's book, or read this web page.

This is also a good opportunity to ensure diverse representation in the experts associate with the course by making sure that training materials created from people with diverse backgrounds are included in these options.

This could also include materials in languages other than English. E.g., The Carpentries ongoing Spanish translation effort.