add styler package

[lorenzwalthert]

1. Which package would you like to suggest? What features does it provide?

I suggest to add the {styler} package to the task view, as an alternative to {formatR}. {styler} has more features than formatR (although it is slower) and has been under active development over the last few years. It is probably also more opinionated than formatR because its formats according to the tidyverse style guide, where the deparse(parse(...)) approach from {formatR} is closer to base R.

2. Please provide the link to CRAN by appending the package name
   (case-sensitive) to the end of the URL below:

https://cran.r-project.org/package=styler

3. Which category do you think is the best fit for the package:

code/data formatting tools

[jdblischak]

@lorenzwalthert Thanks for the suggestion and for maintaining the styler package!