Change "Is filtering logic handled in controller if needed?" to "Is filtering logic handled in a service if needed?"

I suggest changing [Is filtering logic handled in controller if needed?](https://github.com/jvandemo/angularcodereview-com/blob/master/src/angularjs/index.jade#L736) to "Is filtering logic handled in a service if needed?"

The reason behind this is that controllers should be as lean as possible which makes them easy to test. Services should provide filtered data, ready to be consumed by controllers. It also makes filter functions reusable if they are defined in services.

More info can be found in John Papa's guide [Defer Controller Logic to Services](https://github.com/johnpapa/angular-styleguide/blob/master/a1/README.md#style-y035) and [Keep Controllers Focused](https://github.com/johnpapa/angular-styleguide/blob/master/a1/README.md#style-y037), Minko Gechev's guide [Controllers](https://github.com/mgechev/angularjs-style-guide#controllers).