Function to compute the tail correction

## Value

tail returned as numeric vector within a list.

Tail correction is a reimplementation of the calculations developed by Lasse Ylianttila (STUK, Finland), originally in Excel.

## See also

Other spectral data-processing functions:
`MAYP11278_tail_correction()`

,
`check_sn_match()`

,
`linearize_counts()`

,
`merge_raw_mspct()`

,
`new_correction_method()`

,
`ref_correction()`

,
`trim_counts()`

,
`uvb_corrections()`