Feature request: supporting `dplyr::case_when()` statements

[IndrajeetPatil]

For example, the following code

  centrality <- case_when(
    type == "parametric" ~ "mean",
    type == "nonparametric" ~ "median",
    type == "robust" ~ "trimmed",
    type == "bayes" ~ "MAP"
  )

can be aligned to:

  centrality <- case_when(
    type == "parametric"     ~ "mean",
    type == "nonparametric"  ~ "median",
    type == "robust"         ~ "trimmed",
    type == "bayes"          ~ "MAP"
  )

[IndrajeetPatil]

On a second thought, these are not assignments, and so don't lie under the purview of this package.

{styler} already has an issue about this, and that's a more appropriate place for this functionality:
r-lib/styler#733