Fix typo in code example

Removes an errant closing bracket from a code sample.

Author: HeroicEric

README.md

@@ -33,8 +33,7 @@ to your `.template-lintrc.js` file:
 module.exports = {
   plugins: ["ember-template-lint-plugin-prettier"],
 
-  extends: ["recommended", "ember-template-lint-plugin-prettier:recommended"],
-  },
+  extends: ["recommended", "ember-template-lint-plugin-prettier:recommended"]
 };
 ```