<C-v>: to engage Visual-Block mode; then we define the column selection by moving our cursor down several lines
xkey deletes that column,.repeats the deletion for the same range of text.
RESELECT our last visual selection
replace each character in the selection with a pipe character.
we do a quick line-wise yank-and-put to duplicate the top line.
replace every character in that line with a dash character.
