Don’t put ; at the end of a line, and don’t use ; to put multiple commands on one line.

[AshesITR]

The tidyverse style guide specifies essentially ; is forbidden.
Currently, we only don't lint semicolons.

Since our default linters strive to enforce tidyverse style, we should add (and rename?) the semicolon_terminator_linter.

NB this will cause lints in our tests/.