Describe the enhancement requested

After a number of discussions with folks, some documentation improvements which could be made to the pkgdown site:

• link to cheatsheet from "getting started" page
• move "implementations" further down and move up "contributing", CoC, and license (see Distill site as an example)
• simplify first 2 paragraphs in README page (replace with something 10th-12th grade reading age max)
• link to R4DS chapter
• link to Awesome Arrow R

Component(s)

R