Revert "Tweak write_items() to take items by-ref"
Revert "Tweak write_items() to take items by-ref"

This reverts commit 471efc61c75c1137de5650a4adce15ef4b2a14a8.

write_items() is most useful to write a Vec<Item>. If you want to write
a bunch of items that aren't in a vector, just write them individually.

kballard/alfred-rs