Locates reaction times in text of results output from read_results
and
their associated row numbers. The resulting data frame is joined back into
results to include reaction times
reaction_times_parse(text)
returns a data frame with reaction times and row numbers to
eventually be recombined with swimming results inside swim_parse
output from read_results
followed by
add_row_numbers
reaction_times_parse
is a helper function inside
swim_parse