minko suggestion on elements for components

Author: John Papa

public/docs/ts/latest/guide/style-guide.jade

@@ -710,6 +710,8 @@ a(href="#toc") Back to top
       **Why?**: Components have templates containing HTML and optional Angular template syntax. They are most associated with putting content on a page, and thus are more closely aligned with elements.
 
       **Why?**: Components are derived from Directives, and thus their selectors can be elements, attributes, or other selectors. Defining the selector as an element provides consistency for components that represent content with a template.
+      
+      **Why?**: It is easier to recognize that a symbol is a component vs a directive by looking at the template's html.
 
   ```
   /* avoid */