Point from HTTP-Client docs to DI

[Ryuno-Ki]

This issue was originally opened in aurelia/site-generator#30. I've updated the reference here.

Hey there!

I'm currently porting a small demo over to Aurelia from Angular 9 and love it so far!
I'm not sure, whether this repo is still used for updating the website, but …

What is the motivation / use case for changing the behavior?
In HTTP Services you are currently describing, how to build AJAX requests.

You also recommend (typo in the docs!) to:

Instead, we reccommend that you create one or more service classes that encapsulate all HTTP access behind a friendly, application-specific API.

I'd suggest to place a link there to Dependency Injection, because that would describe how the service class would be written.

I discovered the page via a DDG-Search finally.

Thanks for making Aurelia :-)
The project evolved way better (watching your progress since the Skeleton times ;-) )