docs: Fix iframe link in Write Less Code blog post (#11215)

* fix iframe link in Write Less Code blog post

* Update documentation/blog/2019-04-20-write-less-code.md

---------

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

Author: WilliamOConnell

documentation/blog/2019-04-20-write-less-code.md

@@ -40,7 +40,7 @@ Reducing the amount of code you have to write is an explicit goal of Svelte. To
 <div class="max">
 	<iframe
 		title="Simple component example"
-		src="/repl/embed?example=blog-write-less-code"
+		src="/repl/blog-write-less-code/embed?version=3"
 		scrolling="no"
 	></iframe>
 </div>