fix linting error in guide

Author: ljharb

README.md

@@ -2178,7 +2178,6 @@ Other Style Guides
   <a name="control-statement--value-selection"></a>
   - [17.2](#control-statements--value-selection) Don't use selection operators in place of control statements.
 
-
     ```javascript
     // bad
     !isRunning && startRunning();