fix: 翻译了部分多级注入器新增的部分

public/docs/ts/latest/guide/hierarchical-dependency-injection.jade

@@ -63,15 +63,20 @@ figure.image-display
   Every component doesn't need its own injector and it would be horribly inefficient to create
   masses of injectors for no good purpose.
   
-  但Angular实际上并没有为每个组件*创建*一个独立的注入器。
+  Angular实际上并没有为每个组件*创建*一个独立的注入器。
   每个组件并不需要自己的注入器，那样做会非常低效，而且没有好处。
 
   But every component _has an injector_, even if it shares that injector with another component or with the injector of the root `AppModule`.
   And there _may_ be multiple injector instances operating at different levels of the component tree 
   depending upon how the developer registers providers, which is the subject of this guide.
   
+  但是每个组件都*有*一个注入器，它可能共享其它组件的注入器或使用根模块`AppModule`的注入器。
+  而且在组件树的不同层次上还*可能有*多个注入器实例，这取决于开发人员如何注册这些提供商。这正是本章的主题。
+
   ### Injector bubbling  
   
+  ### 注入器"冒泡"
+
   When a component requests a dependency, Angular tries to satisfy that dependency with a provider registered in that component's own injector.
   If the component's injector lacks the provider, it passes the request up to its parent component's injector.
   If that injector can't satisfy the request, it passes it along to *its* parent injector.