Add documentation hint regarding factory and fileless service activation

[mortenn]

The documentation said to modify your svc files, but the same can be done in web.config:

<system.serviceModel>
  <serviceHostingEnvironment>
    <serviceActivations>
      <add factory="SimpleInjector.Integration.Wcf.SimpleInjectorServiceHostFactory,
            SimpleInjector.Integration.Wcf"
        service="Some.Namespace.API" relativeAddress="Some.Namespace.API.svc"/>
    </serviceActivations>
  </serviceHostingEnvironment>
</system.serviceModel>

This also allows for file-less service activation.

[dotnetjunkie]

That's a great suggestion. I'll take a look if I can add this to the documentation.

[dotnetjunkie]

Moved issue to the Documentation repo.