Make lint happy

Author: aomarks

CHANGELOG.md

@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - **POTENTIALLY BREAKING** Upgraded CodeMirror to v6
 
 ### Added
+
 - Added `extensions` property to `<playground-ide>`,
   `<playground-file-editor>`, and `<playground-code-editor>` for applying
   programmatic CodeMirror extensions.