container:start repeats itself very early on,

acknowledge this in the writing.

src/_10_hello_world.md

@@ -24,8 +24,8 @@ class MyScalatraFilter extends ScalatraFilter with ScalateSupport {
   }
 }
 {pygmentize}
-     
-Back at the shell prompt, from your project root, you can run the project
+
+If you haven't already done so, from your project root, you can run the project
 with:
 
 {pygmentize::}
@@ -36,4 +36,4 @@ $ sbt
 The application starts on [http://localhost:8080](http://localhost:8080).  As
 you can see, Scalatra doesn't force you to setup much infrastructure: a
 request to a URL evaluates some Scala code and returns some text in response.
-Whatever the block returns is sent back to the browser.
+Whatever the block returns is sent back to the browser.