Remove reference to hello-aws-javascrip template in blogpost

[desteves]

Blog post: /blog/building-your-first-serverless-app-using-only-javascript/ contains a reference to the hello-aws-javascript template. However upon closer inspection we've determined that this template belongs in the examples repo instead. To avoid breaking anything we'd need to refresh the steps listed in the blog to point to the new location of the code

Related templates issue

[cnunciato]

to avoid breaking anything

Moving the template will break external references to it, though. Left a comment here -- I'd personally prefer we kept the template where it is, but we can discuss further if y'all disagree.