Java Edition 17w15a

17w15a is the fifth snapshot released for 1.12.

Changes

 * Added descriptions to advancements & changed some titles. It's not entirely final, but we're getting there!
 * Added colored beds! You can craft them with coloured wool or dying a white bed
 * Players shouldn't be getting kicked from servers randomly now, and both recipe book & advancements should work fine in multiplayer
 * The recipe book is a lot more stable, hopefully no longer duplicating items
 * Added a toast notification for toggling the narrator
 * Added the option to toggle narrator between: off, chat & system, chat only, system messages only
 * Made stairs a little more solid, allowing torches, fences, glass panes, walls & snow to connect to them properly
 * Reintroduced the book recipe. Sorry about that!
 * Made the "recipe unlocked" toast show which items were unlocked, and appear when you've actually unlocked new recipes