Improve quick start example

Co-authored-by: Joe Mooring <joe@mooring.com>

content/en/getting-started/quick-start.md

@@ -110,7 +110,7 @@ Press `Ctrl + C` to stop Hugo's development server.
 Add a new page to your site.
 
 ```text
-hugo new content posts/my-first-post.md
+hugo new content content/posts/my-first-post.md
 ```
 
 Hugo created the file in the `content/posts` directory. Open the file with your editor.