tweak (sveltejs#540)

Co-authored-by: Rich Harris <[email protected]>

Author: Rich-Harris

content/tutorial/02-advanced-svelte/01-motion/01-tweens/README.md

@@ -6,7 +6,7 @@ Now that we've covered the basics, it's time to learn some advanced Svelte techn
 
 Setting values and watching the DOM update automatically is cool. Know what's even cooler? Tweening those values. Svelte includes tools to help you build slick user interfaces that use animation to communicate changes.
 
-Let's start by changing the `progress` store to a `tweened` value:
+Let's start by changing the `progress` store to a `tweened` store:
 
 ```svelte
 /// file: App.svelte