Update QLDoc for getATemplateArgument

Co-authored-by: Erik Krogh Kristensen <erik-krogh@github.com>

Author: asgerf

javascript/ql/src/semmle/javascript/frameworks/Angular2.qll

@@ -356,7 +356,13 @@ module Angular2 {
     /** Gets an HTML element that instantiates this component. */
     HTML::Element getATemplateInstantiation() { result.getName() = getSelector() }
 
-    /** Gets an argument that flows into the `name` field of this component. */
+    /** 
+      * Gets an argument that flows into the `name` field of this component. 
+      * 
+      * For example, if the selector for this component is `"my-class"`, then this  
+      * predicate can match an attribute like: `<my-class [foo]="1+2"/>`.  
+      * The result of this predicate would be the `1+2` expression, and `name` would be `"foo"`. 
+      */
     DataFlow::Node getATemplateArgument(string name) {
       result =
         getAttributeValueAsNode(getATemplateInstantiation().getAttributeByName("[" + name + "]"))