[guide] Add link to eol-last rule.

ljharb · ljharb · commit a9bfee01cd45 · 2016-07-09T09:10:50.000-07:00
Fixes airbnb#945.
diff --git a/README.md b/README.md
@@ -1922,7 +1922,7 @@ Other Style Guides
     ```
 
   <a name="whitespace--newline-at-end"></a><a name="18.5"></a>
-  - [18.5](#whitespace--newline-at-end) End files with a single newline character.
+  - [18.5](#whitespace--newline-at-end) End files with a single newline character. eslint: [`eol-last`](https://github.com/eslint/eslint/blob/master/docs/rules/eol-last.md)
 
     ```javascript
     // bad
