Converts a vector of strings to snake_case by inserting underscores between words and converting all characters to lowercase. It also replaces spaces with underscores.
Examples
snake_case(c("Normal 1991_2020 AHM", "Normal 1991_2020 bFFP"))
#> [1] "normal_1991_2020_ahm" "normal_1991_2020_b_ffp"
# Returns: c("normal_1991_2020_ahm", "normal_1991_2020_b_ffp")