Code to Implement

file:	src/main/sml/warm_up_remove_first/remove_first.sml
functions:	remove_first

remove_first

fun remove_first(xs : ''a list, target : ''a) : ''a list =
     raise NotYetImplemented

Remove the first item which matches target if it exists. For example, remove_first([1,2,3,4,5], 3) should return the list [1,2,4,5].

If the target does not exist, return the complete list. For example, remove_first([1,2,3,4,5], 6) should return the list [1,2,3,4,5].

file:	unit_test_remove_first.sml
source folder:	src/test/sml/warmup_remove_first