a few more changes, incorporating thso's feedback

still more to do...

Author: kwalrath

public/docs/_examples/dependency-injection/dart/lib/heroes/hero_service.dart

@@ -16,7 +16,9 @@ class HeroService {
   List<Hero> getHeroes() {
     var auth = _isAuthorized ? 'authorized' : 'unauthorized';
     _logger.log('Getting heroes for $auth user.');
-    return HEROES.where((hero) => _isAuthorized || !hero.isSecret).toList();
+    return HEROES
+        .where((hero) => _isAuthorized || !hero.isSecret)
+        .toList();
   }
 // #enddocregion internals
 }

public/docs/_examples/dependency-injection/dart/lib/providers_component.dart

@@ -149,7 +149,7 @@ class ProviderComponent6a {
     template: '{{log}}',
     providers:
         //#docregion providers-6b
-        // Alias OldLogger w/ reference to NewLogger
+        // Alias OldLogger with reference to NewLogger
         const [NewLogger, const Provider(OldLogger, useExisting: NewLogger)]
        //#enddocregion providers-6b
 )

public/docs/dart/latest/guide/dependency-injection.jade

@@ -126,6 +126,13 @@ include ../_util-fns
 +includeShared('{ts}', 'logger-service-1')
 +makeExample(
   'dependency-injection/dart/lib/logger_service.dart',null, 'lib/logger_service')
+.l-sub-section
+  :marked
+    ### Implementing a logger
+
+    Our examples use a simple logger.
+    A real implementation would probably use the
+    [logging package](https://pub.dartlang.org/packages/logging).
 :marked
   We're likely to need the same logger service everywhere in our application,
   so we put it in the `lib/` folder, and