change "item" to "thing"

The text in the button is "Remove first thing".

site/content/tutorial/04-logic/05-keyed-each-blocks/text.md

@@ -4,7 +4,7 @@ title: Keyed each blocks
 
 By default, when you modify the value of an `each` block, it will add and remove items at the *end* of the block, and update any values that have changed. That might not be what you want.
 
-It's easier to show why than to explain. Click the 'Remove first item' button a few times, and notice that it's removing `<Thing>` components from the end and updating the `value` for those that remain. Instead, we'd like to remove the first `<Thing>` component and leave the rest unaffected.
+It's easier to show why than to explain. Click the 'Remove first thing' button a few times, and notice that it's removing `<Thing>` components from the end and updating the `value` for those that remain. Instead, we'd like to remove the first `<Thing>` component and leave the rest unaffected.
 
 To do that, we specify a unique identifier for the `each` block: