Use magrittr pipe with text_summary()

[jdblischak]

The new function text_summary() uses the native pipe (#526), which produces the following warning from R CMD build:

  NB: this package now depends on R (>= 4.1.0)
  WARNING: Added dependency on R >= 4.1.0 because package code uses the
  pipe |> or function shorthand \(...) syntax added in R 4.1.0.
  File(s) using such syntax:
    ‘text_summary.R’ ‘text_summary.Rd’

Currently our plan is to continue to support R >=3.5, so we need to use the magrittr pipe in the source code and examples (#517)

[nanxstats]

Looking good. Once any of the Imports start to require R >= 4.1.0, we can bump it and switch to native pipes. So far all the Imports are all staying on >= 3.5 or so.

[LittleBeannie]

Thank you, @jdblischak, for catching this. This is an area I need to pay closer attention to in order to avoid future occurrences!