fix(wording & style) small fix on wording and text style

Author: Guikingone

service_container/injection_types.rst

@@ -324,6 +324,8 @@ which allow the container to return the newly created service:
 This approach is useful if you need to configure your service according to your needs, 
 so, what are the advantages?
 
-* Your service become immutable, as Symfony will return a new object, the initial service stay clean and unchanged.
+* Your service becomes immutable, as the container will return a new object, 
+  the initial service stays clean and unchanged.
 
-* You can easily change the injected service as long as it respect the interface asked by the initial service.
+* You can easily change the injected service as long as it respect the interface 
+  asked by the initial service.