Java Edition 1.12-pre3

1.12-pre3 is the third pre-release for 1.12.

General

 * Added resistance to "how did we get here?" hidden challenge
 * Gave "how did we get here?" hidden challenge a big experience reward
 * Added more food items to "a balanced diet" challenge
 * Advancements will now remember the tab you last selected
 * The tutorial hints will be a little more smarter about deciding if now is a good time to learn how to punch wood
 * Added new keybinding for opening advancements (default "L")
 * Huge optimizations to both recipe book & creative inventory searching
 * Some optimizations to advancements
 * Technical: Changed "requirements" of advancements to an AND of ORs
 * Technical: Functions should now use file extension ".mcfunction"
 * Technical: Functions should not prefix commands with "/" (forwards slash)
 * Technical: Functions should only use "#" to comment (not "//")
 * Technical: Functions should recurse as expected, even whilst mixing /function and /execute
 * Technical: Functions should only use "#" to comment (not "//")
 * Technical: Functions should recurse as expected, even whilst mixing /function and /execute

Parrot

 * Changed parrots to be fed with seeds, not cookies
 * Allowed parrots to spawn in old jungles