docs(ngmodule): Fix typo of italic in backquote

closes #2106
The underscore would turn to real underscore character within backquote.

Author: trotyl

public/docs/ts/latest/guide/ngmodule.jade

@@ -1519,7 +1519,7 @@ a#q-when-entry-components
 :marked
   ### When do I add components to _entryComponents_?
 
-  Most application developers won't need to add components to the `_entryComponents_`.
+  Most application developers won't need to add components to the `entryComponents`.
 
   Angular adds certain components to _entry components_ automatically.
   Components listed in `@NgModule.bootstrap` are added automatically.