include example code output in docs

**I'm submitting a feature request**
- **Language:**
all

Does the Aurelia Docs assume that the reader will be executing the code in the examples? I feel like the output from the code examples should be included too, for those who are not first timers.

If it is expected that the reader should run the code it would be helpful to include a [GistRun](https://gist.run/?id=5806829eed47bd9e819d) with a playground already set up

Start by reviewing the Aurelia Docs code examples and the linked GistRun playground to determine which examples need visible output or an executable setup. Define the scope and presentation consistently across the documentation, then verify that readers can understand each example without running it or can launch the provided playground.

Written by the indexing model from the issue text.