[7.1] add link to fn names discussion. fixes airbnb#794

Author: hshoff

README.md

@@ -548,7 +548,7 @@ Other Style Guides
   <a name="functions--declarations"></a><a name="7.1"></a>
   - [7.1](#functions--declarations) Use function declarations instead of function expressions. eslint: [`func-style`](http://eslint.org/docs/rules/func-style) jscs: [`requireFunctionDeclarations`](http://jscs.info/rule/requireFunctionDeclarations)
 
-    > Why? Function declarations are named, so they're easier to identify in call stacks. Also, the whole body of a function declaration is hoisted, whereas only the reference of a function expression is hoisted. This rule makes it possible to always use [Arrow Functions](#arrow-functions) in place of function expressions.
+    > Why? Function declarations are named, so they're easier to identify in call stacks. Also, the whole body of a function declaration is hoisted, whereas only the reference of a function expression is hoisted. This rule makes it possible to always use [Arrow Functions](#arrow-functions) in place of function expressions. ([discussion](https://github.com/airbnb/javascript/issues/794))
 
     ```javascript
     // bad